Carbonate Petrography

Carbonate petrography is the study of limestones, dolomites and associated deposits under optical or electron microscopes greatly enhances field studies or core observations and can provide a frame of reference for geochemical studies.

25 strangest Geologic Formations on Earth

The strangest formations on Earth.

What causes Earthquake?

Of these various reasons, faulting related to plate movements is by far the most significant. In other words, most earthquakes are due to slip on faults.

The Geologic Column

As stated earlier, no one locality on Earth provides a complete record of our planet’s history, because stratigraphic columns can contain unconformities. But by correlating rocks from locality to locality at millions of places around the world, geologists have pieced together a composite stratigraphic column, called the geologic column, that represents the entirety of Earth history.

Folds and Foliations

Geometry of Folds Imagine a carpet lying flat on the floor. Push on one end of the carpet, and it will wrinkle or contort into a series of wavelike curves. Stresses developed during mountain building can similarly warp or bend bedding and foliation (or other planar features) in rock. The result a curve in the shape of a rock layer is called a fold.

Aventurine Gemstone

What is Aventurine?

Aventurine is a form of quartz, characterised by its translucency and the presence of platy mineral inclusions that give a shimmering or glistening effect termed aventurescence.

The most common colour of aventurine is green, but it may also be orange, brown, yellow, blue, or gray. Chrome-bearing fuchsite (a variety of muscovite mica) is the classic inclusion, and gives a silvery green or blue sheen. Oranges and browns are attributed to hematite or goethite. Because aventurine is a rock, its physical properties vary: its specific gravity may lie between 2.64-2.69 and its hardness is somewhat lower than single-crystal quartz at around 6.5.

Aventurine feldspar or sunstone can be confused with orange and red aventurine quartzite, although the former is generally of a higher transparency. Aventurine is often banded and an overabundance of fuchsite may render it opaque, in which case it may be mistaken for malachite at first glance.

The name aventurine derives from the Italian "a ventura" meaning "by chance". This is an allusion to the lucky discovery of aventurine glass or goldstone at some point in the 18th century. Although it was known first, goldstone is now a common imitation of aventurine and sunstone. Goldstone is distinguished visually from the latter two minerals by its coarse flecks of copper, dispersed within the glass in an unnaturally uniform manner. It is usually a golden brown, but may also be found in blue or green.

The majority of green and blue-green aventurine originates in India (particularly in the vicinity of Mysore and Chennai) where it is employed by prolific artisans. Creamy white, gray and orange material is found in Chile, Spain and Russia. Most material is carved into beads and figurines with only the finer examples fashioned into cabochons, later being set into jewellery.

Aventurine healing Properties

Green Aventurine carries a strong connection to Earth and the devic kingdom, providing a better understanding and appreciation of nature and its soothing vibrations upon the mind and body. It is an excellent stone for gridding houses or gardens against geopathic stress. 
Wearing Aventurine also absorbs electromagnetic smog and guards against environmental pollution. Taped to a cell phone, it protects against its emanations. 
Green Aventurine energetically stimulates the physical growth of premature infants, young children and teenagers. It increases overall vitality and enhances the intellectual development of children struggling with schoolwork and destructive hyperactivity. It assists adults with written work, typing and computer skills, and is beneficial to all in overcoming clumsiness.
Aventurine may be made into an elixir to drink or used in ablutions by soaking a stone fragment in demineralized water overnight (we recommend the indirect method). It is highly beneficial for fighting eczema, rosacea, juvenile acne, and other skin problems. 
Aventurine is ideal for soothing quick-tempers or brutal temperaments, and can greatly diminish the effects of domestic strife between spouses. 
For those looking for love in their mature years, Green Aventurine may be used as a love crystal or added to a Heart Chakra layout as it encourages love later in life.

Physical properties of Aventurine

Chemical FormulaSiO2
ColourBlue, Green, Yellow, Orange, Brown, Gray
Hardness6.5 - 7
Crystal SystemHexagonal
Refractive Index1.54 - 1.55
SG2.63 - 2.65
TransparencyOpaque. May be translucent when backlit on the edges.
Double Refraction.009
LusterVitreous, waxy
Mineral ClassQuartz / Chalcedony

Aquamarine Gemstone

What is aquamarine?

Aquamarine is a member of the beryl family. This stone is known for its blue to blue-green colour. The name comes from the Latin for “sea water”, and aquamarine folklore is usually tied to sailors and the sea. Aquamarine is the birthstone for March and it’s a popular gem that wears well, is readily available, and moderately priced.
Aquamarine is a member of the beryl family and ranges in colour from an almost colourless pale blue to blue-green or teal. The most prize colour is a deep-blue aqua colour. It is 7.5-8 on the Mohs scale of hardness and gets its name from Latin words meaning water and sea.


The most valuable aquamarines come from Brazil, but it is also mined in Kenya and Nigeria, Madagascar, Zambia, Tanzania, Sri Lanka, Pakistan, Afghanistan and Russia. . Aquamarines on the market today are usually faceted, but when cut as a cabochon, they may display a cat's eye effect known as asterism.
Some gemstones are heated to high temperatures to enhance the colour and/or clarity of a stone. Aquamarines are often heat treated to change a blue-green or teal coloured stone to a pure blue. This results in a permanent colour change.

Aquamarine Healing Properties

Associated with the Throat chakra, Aquamarine helps overcome the fear of speaking, and is an excellent stone for teachers and presenters of all types. It relaxes speakers to a stage of consciousness in which they are fully aware of their own truths, wisdom and feelings, and able to articulate them with clarity and conviction. It also allows one to speak clearly and without anger in difficult situations. 
Aquamarine accelerates the intellectual reasoning processes and enhances the ability for rapid response. It makes one unconquerable through learning, not only about the physical world, but about oneself.  It bestows perseverance, discipline and light heartedness.
Aquamarine encourages the ideal of service to the world and to the development of a humanity attuned to healing. It emits a gentle and compassionate energy, promoting moderation and responsibility for ones' actions. It inspires judgemental people to be more tolerant, and helps those overwhelmed by responsibility to find order. 
A stone of natural justice, Aquamarine utilises compromise and negotiation, and gives quiet courage and clear reasoned words in confrontational situations. Pass Aquamarine over any written complaints you receive or before you send any out, wear or carry Aquamarine when visiting your child's school because of a complaint, or when resolving neighbourhood disputes over parking or boundaries. 
As a travel crystal, greenish blue Aquamarine protects those who journey by sea, alleviating the fear of water, and guards those involved in any long-haul travel such as flying or driving long distances. It is a good stone for learning to swim. 
As a love crystal, pale blue Aquamarine encourages a lover to return, helps two people with different lifestyles to live together in harmony, and reduces the effects of sensitive issues that cause quarrels. Aquamarine is often given as a love token or eternity ring, and increases commitment and fidelity "as long as the waters of the earth flow."

Physical Properties of Aquamarine

Chemical FormulaBe3Al2SiO6
Hardness7.5 - 8.0
Crystal SystemHexagonal
Refractive Index1.57 - 1.58
SG2.6 - 2.8
TransparencyTransparent to translucent
Double Refraction.006
Cleavage3,1 - basal
Mineral ClassBeryl (Aquamarine)

Andradite Gemstone

What is Andradite?

Andradite is a species of the garnet group. It was named after the Brazilian mineralogist José Bonifácio de Andrade e Silva (1763–1838). Andradite includes three varieties:
  1. Melanite: Black in color, referred to as "titanian andradite".
  2. Demantoid: Vivid green in color, one of the most valuable and rare stones in the gemological world.
  3. Topazolite: Yellow-green in color and sometimes of high enough quality to be cut into a faceted gemstone, it is rarer than demantoid.
It was first described in 1868 for an occurrence in Drammen, Buskerud, Norway.


It occurs in skarns developed in contact metamorphosed impure limestones or calcic igneous rocks; in chlorite schists and serpentinites and in alkalic igneous rocks (typically titaniferous). Associated minerals include vesuvianite, chlorite, epidote, spinel, calcite, dolomite and magnetite. It is found in Italy, the Ural Mountains of Russia, Arizona and California and in Dnipropetrovsk Oblast in Ukraine. Like the other garnets, andradite crystallizes in the cubic space group, with unit-cell parameter of 12.051 Å at 100 K. The spin structure of andradite contains two mutually canted equivalent antiferromagnetic sublattices below the Néel temperature.

Andradite Healing Properties

The energies and healing powers of Andradite Garnet reflect the strength and protection of all garnets. Its physical healing power encourages the stimulation and regeneration of blood, the assimilation of vital minerals, and strengthens the immune system.
Emotionally, Andradite Garnet brings strength, stability and balance, promoting self-confidence and self-esteem. It is associated with the Base, Heart and Solar Plexus Chakras, opening up the mind to higher thinking and better relationships, and stimulating creativity, will and focus.
It is a powerful spiritual cleanser. Andradite Garnet ranges in colour energy from green to dark olive, deep yellow, and a glossy black. Melanite, the black variety is an excellent meditation aid with powerful grounding abilities.
A host of angels are associated with Andradite's colour energies and it honors two Goddesses. Garnet is the traditional birthstone of January, and Andradite is the natural birthstones of those born in the in the heart of spring (April 20-May 20) and the beginning of summer (June 21-July 21).
Garnet is the zodiac stone for those born under the sign Aquarius, and is an Enhancer Strengthener crystal. It has the properties of Wood and Water energies, and is a talisman of protection.

Physical Properties of Andradite

Chemical FormulaCa3Fe3+2Si3O12
ColourRed, Green, Yellow, Orange, Brown, Pink, Gray, Black, Multicoloured
Hardness6.5 - 7.5
Crystal SystemIsometric
Refractive Index1.888 - 1.889
SG3.8 - 3.9
TransparencyTransparent to opaque
Double RefractionNone
LusterAdamantine, submetallic
Mineral ClassAndradite (Garnet)

Andesine gemstone

What is Andesine?

Andesine is a silicate mineral, a member of the plagioclase feldspar solid solution series. Its chemical formula is (Ca, Na)(Al, Si)4O8, where Ca/(Ca + Na) (% Anorthite) is between 30%-50%. The plagioclase feldspars are a continuous solid solution series and as such the accurate identification of individual members requires detailed optical study, chemical analysis or density measurements. Refractive indices and specific gravity increase directly with calcium content.
Andesine feldspar is composed of 50-70% albite and 30-50% anorthite. 

Name and discovery

Andesine was first described in 1841 for an occurrence in the Marmato mine, Colombia. It is named after the Andes mountains of South America. The name is for the Andes due to its abundance in the andesite lavas in those mountains. 
Andesine is found in a range of colours, from red, honey-red to orange, yellow, champagne and green. In the early 2000s, red and green gemstones began to be marketed under the name of 'Andesine'. After some controversy, these gemstones were subsequently discovered to have been artificially-coloured.


Andesine occurs in intermediate igneous rocks such as diorite, syenite and andesite. It characteristically occurs in metamorphic rocks of granulite to amphibolite facies commonly exhibiting antiperthite texture. It also occurs as detrital grains in sedimentary rocks. It is commonly associated with quartz, potassium feldspar, biotite, hornblende and magnetite.

Andesine Healing Properties

As a protective stone, wearing andesine jewellery or simply carrying the stone around will prevent the release of necessary energies while also acting to deflect undesirable energy. Use when around particularly negative people or situations. Wearing a labradorite pendant is beneficial for sensitive people.
Like all metaphysical crystals andesine gemstone can impact the mind, thought-patterns, and psychological well-being. This stone acts to connect the intuition with the intellect. What effect does this synergy have? It facilitates creative thought, which is ideal for innovators, therapists, writers, and any work where the combination of concrete thoughts and deeper awareness is appreciated.

Physical Properties of Andesine

Chemical Formula(Na,Ca)Al1-2Si3-2O8
ColourRed, Green, Yellow, Orange, Pink, Multicoloured
Hardness6 - 6.5
Crystal SystemTriclinic
Refractive Index1.560 - 1.568
SG2.69 - 2.70
TransparencyTransparent to translucent
Double Refraction.008
Cleavage2,1 - basal ; 2,1 - prismatic ; 3,1 - pinacoidal.
Mineral ClassPlagioclase feldspar (Also see the minerals Andesine and Labradorite))

Andalusite and Chiastolite

What is Andalusite?

Andalusite is a rock-forming mineral that is mined for use in high-temperature refractories. Gem-quality specimens are cut into faceted gems and cabochons. Andalusite forms during the regional metamorphism of shale. It is found in schist and gneiss at some present and ancient convergent plate boundaries where the rocks have been exposed to the temperatures and pressures needed for its formation. In these rocks, andalusite is often associated with kyanite and sillimanite.
Andalusite also forms during the contact metamorphism of argillaceous rocks. In this situation, it can form within the metamorphosed rock or in veins and cavities within the igneous rock. It can be associated with cordierite in hornfels, granite, and granitic pegmatite.
Andalusite gets its name from the Spanish province of Andalusia, where it was first discovered. Andalusite is an aluminium silicate that has been called the "poor man's alexandrite." Some andalusite crystals have inclusions arranged so that in cross-section, they form a dark cross. This form of andalusite is called chiastolite, which is a name that comes from the Greek word for cross. Chiastolite occurs in schists and can be found in Santiago de Compostela, a town in Northwest Spain. In the past, many amulets made of chiastolite were sold to pilgrims. Andalusite is heated to form mullite, a mineral that has many industrial uses. For example, mullite is used in the manufacturing of spark plugs. Andalusite is a polymorph with two other minerals, kyanite and sillimanite. It is a pleochroic stone; it can display shades of colour varying from light yellowish brown to green brown, light brownish pink, greyish green, or definite green, with pleochrism, making it hard to identify the main colour.

What is Chiastolite?

Chiastolite is a variety of andalusite that contains black particles of graphite arranged in geometric patterns. The graphite is pushed aside by crystal growth within a rock that is being metamorphosed. As growth occurs, the particles become concentrated at crystal interfaces. The result can be a cross-shaped pattern within the mineral - similar to the "cross-stone" shown in the photo here. People have known about these cross stones for centuries and have valued them for their perceived religious or spiritual meaning. Attractive specimens are often cut and polished for use as amulets, charms, and novelty gems.


Transparent green andalusite is the most valued form of andalusite. Unlike other pleochroic gemstones, such as iolite and zoisite, where gem cutters try to reduce the pleochrism and highlight the single best colour, cutters of andalusite actually attempt to get a good mix of colours in the stone. When cut in an emerald cut, andalusite may look mostly green, with bits of orange showing at the ends of the emerald shape. When cut in a round cut, the green body colour is visible, as are simultaneous flashes of other colours. The rare and sometimes expensive emerald green coloured variety may exhibit a bright yellow colour simultaneously, or when viewed from different angles. In contrast, the pink variety does not exhibit this kind of colour phenomenon.


Andalusite is a fairly durable stone, rating a 7 to 7.5 on the hardness scale. It is a vitreous and transparent to translucent stone. Andalusite occurs as crystals with poor luster, typically in thermally metamorphosed peltic rocks, and in muddy rocks that have been metamorphosed under low-pressure conditions. It also occurs, together with corundum, tourmaline, topaz and other minerals, in some pegmatites. Andalusite is found mainly as water worn pebbles and it is these pebbles that are usually cut as gemstones.

Physical Properties and Uses of Andalusite

Andalusite has a number of useful physical properties. It has the ability to withstand high temperatures without alteration. For that reason it is used to make high-temperature ceramics and refractories. The white porcelain of many spark plugs is made using andalusite.
Andalusite is one of a small number of minerals that commonly forms prismatic crystals with a square cross-section. This can be important information for identification in the field.
Transparent specimens of andalusite are often strongly pleochroic. This makes them have different apparent colours when viewed from different directions. This pleochroic effect allows andalusite to be cut into unique gemstones.
Although twinning is not common in andalusite, nicely crystallised specimens that possess twinning can be distinctive.
Chemical FormulaAl2SiO5
ColourWhite, Green, Yellow, Orange, Brown, Pink, Gray, Black, Multicolored
Hardness7 - 7.5
Crystal SystemOrthorhombic
Refractive Index1.62 - 1.65
SG3.1 - 3.2
TransparencyTransparent to opaque
Double Refraction-0.01
Mineral ClassAndalusite


Beautiful dark green forms of adalusite come from alluvial gravels in Sri Lanka, while green andalusite gemstones are found in Brazil, principally in the states of Espirito Santo and Minas Gerais. Andalusite from Brazil is small, rare and very expensive. Brazil is actually the primary source for andalusite. Large columnar crystals of andalusite occur at Lisenz, Austria. Andalusite also occurs in the United States in Massachusetts, the White Mountains in California, Standish, Maine, and Delaware County, Pennsylvania. Other important sites for andalusite include Canada, Bimbowrie Australia, the Hunan Province in China, as well as various locations around Siberia, Russia, Brittany, France, and England. It has been said that the person who is attracted to this stone is a fighter. However, by wearing the stone, the wearer supposedly becomes wise, gives up fighting, and starts to embark on the path of love. With andalusite, the wearer perceives that with fighting, we live contrary to our own nature.

Andalusite as an Indicator Mineral

Andalusite, kyanite, and sillimanite all share the chemical composition of Al2SiO5. However, they have different crystal structures. Their crystal structure differs because they form under extremely different conditions of temperature and pressure. The phase diagram at left summaries the conditions under which these minerals form.
Andalusite is the low-temperature mineral of the three. Sillimanite is the high-temperature mineral, and kyanite forms at high pressures and lower temperatures.

Andalusite Healing Properties

Andalusite is sometimes called "The Seeing Stone" because it is used in metaphysical works to calmly see the various parts of one's character without bias. It is also reported to be helpful to see the different sides of a problem, and is used for scrying.
Andalusite is said to enhance memory and recall. It is also said to bring chivalry. Andalusite is said bring moderation and balance. It is also a stone that is said to be helpful for meditation and centring.
Physically andalusite is used in crystal healing and folk healing for AIDS, eye problems, deficiencies in calcium, oxygen, iodine, and water retention.
Note that healing crystal meanings are spiritual supports to healing and are not prescriptions or healthcare information.
Andalusite is associated with the solar plexus and heart chakras.

Earthquake Early Warning. How does it work?

Ametrine Gemstone

What is Ametrine?

Ametrine also known as Trystine or by it’s trade name Bolivianite, Ametrine is a naturally occurring variety of quartz. It is a “mixture” of Amethyst and Citrine with zones of purple and of yellow or orange, but yet being a crystal of it’s own volition it is not just a mixture but a shade of it’s two cousins. Most commercially available Ametrine is found in the mines of Bolivia, although there have been some deposits found in Brazil as well as India.
The colouring is due to differing oxidation of iron states within the crystal itself, which occurs due to a temperature gradient across the crystal during the time of it’s formation. In order for the Iron to produce both colours within the same crystal, very specific conditions must be present. Not only must there be two separate temperature conditions, they must also remain stable within the entire growth process of the crystal, which is an incredible feat indeed.
Geologists have theorized that within the Anahi mine, just the specific type of heat was flowing in the right direction across a portion of the crystal to create just enough heat to create the perfect balance of heat and cool for the Ametrines to be formed. If the heat would have been any degree higher or lower these lovelies would have become either Amethyst or Citrines. It is told that there are only two places on the planet with this specific heat index to create Ametrine gemstones, the original mine in Bolivia as well as the Hyderabad mine in India.
The Anahi Mine is in a dolomitic limestone of the Murcielago Group, a sequence of limestones up to 1500 feet thick that dip to the southwest in the area of the mine. Some zones within the Murcielago Group are heavily silicified, causing them to resist weathering and stand up above the surrounding Pantanal lowlands as prominent north-south-trending ridges. The Anahi Mine is in a ridge at a location where the dolomitic limestone is faulted and silicified. Most of the mining activity is done underground, with a small amount of production at the surface. 
Hydrothermal activity has facilitated the growth of quartz within fractures and vugs of the dolomitic limestone. The walls of these openings are often covered with a thick layer of massive quartz with euhedral quartz crystals growing inwards towards the centre of the cavities. Some of these are crystals of ametrine; many have been etched by later hydrothermal activity.

What Gives Ametrine Its Colour?

The colours of amethyst and citrine are produced by iron impurities with different oxidation states within the quartz. Purple is thought to be produced by Fe3+ that is oxidized to Fe4+ by natural radiation emitted by the decay of potassium-40 in nearby rocks. The golden-yellow is thought to be produced by Fe3+.
If a well-formed ametrine crystal is sawn perpendicular to the c-axis, the colour zones of amethyst and citrine often form a geometric pattern that radiates outwards from the c-axis like the pieces of a pie. Straight-line contacts separate zones of amethyst from zones of citrine. This pattern is formed by Brazil law twinning in which two quartz crystals of different colour are intergrown to form the bicolour gemstone. It is very different from the bicolour zones of a tourmaline crystal which form by sequential crystallisation.

History of Ametrine

According to legend, the Ayoreo Indian tribe of eastern Bolivia knew about the bicolour quartz crystals over 500 years ago. Perhaps the earliest formal documentation of natural quartz crystals with zonal colouring of purple and yellow is in a 1925 issue of American Mineralogist. These were basal sections of quartz crystals with colour sectors alternating between purple and yellow. 
Reports of a quartz gemstone of mixed purple and yellow colour being produced anywhere in the world begin in the 1960s from vague localities in Brazil, Bolivia, and Uruguay. Because the material was not attributed to a specific mine, some people believed it was produced synthetically, produced by treating amethyst, or mined illicitly. 
In 1989, changes to Bolivian mining laws allowed gemstone mining in eastern Bolivia, and a company, Minerales y Metales del Oriente S.R.L., obtained exclusive mining rights to a few thousand acres. Their property included a mine location with evidence of a long history of illicit mining. To establish credibility in the gemstone trade, the company invited geologists and gemologists to the mine and allowed them to confirm for themselves that the ametrine and citrine produced there were natural.
Today, their Anahi Mine is the world's only important commercial source of natural ametrine and anahite (a clear variety of quartz with a very light tint of lilac). The mine also produces amethyst, citrine, and bicolour materials that are a combination of amethyst and clear quartz (bicolour amethyst) or citrine and clear quartz (bicolor citrine).

Ametrine Gemstones

A crystal containing both amethyst and citrine in contact with one another can be called "ametrine." These crystals usually contain zones of clear quartz, amethyst, and citrine. When these crystals are cut into pieces that are appropriately sized for faceting gemstones, only a portion of the stones will be ametrine. The remainder will be amethyst, citrine, and clear quartz. This is why the Anahi Mine produces a variety of gem materials and why the amount of ametrine produced is limited.
Some of the early people involved in illicit production from the Anahi mine site were intent to produce amethyst and citrine. The novelty of a bicolour gemstone began when some lapidaries, inspired by bicolour tourmaline, began producing emerald-cut stones that were 50% amethyst and 50% citrine with the colour boundary oriented perpendicular to the table of the stone. These stones were very attractive and desirable to people who saw them. The bicolour material then became a focus of production.
When Minerales y Metales del Oriente S.R.L. took over the mine, much of the production was being sold as cutting rough and mineral specimens. Since then the owner has worked to diversify revenue by developing the staff and facilities needed to cut the stones, design jewellery, manufacture jewellery, and market the rough, the loose stones, and finished jewellery. Now a large portion of the world's ametrine gemstones are taken from the Earth and delivered to the end consumer through a few related companies located in Bolivia. 
New methods of cutting have been developed to make maximum use of a finite ametrine resource. Some stones are still cut in the traditional emerald cut with a 50/50 amethyst/citrine split. Others are cut into "blended ametrine" that has random or planned patches of amethyst and citrine. These stones are cut in orientations that allow light penetrating the stone to pass through zones of purple amethyst and golden-yellow citrine. This can yield beautiful stones with face-up colours that include peach, magenta, and orange.

Ametrine Healing Properties

Wearing Ametrine jewellery may be helpful to you, and may provide you with ways to let go of stress, as they help to create peace and inner harmony.
It is an extremely useful tool for those in the healing profession to utilise. As well it is also very helpful for the average person to use, to work on themselves at home.
If you are working on losing weight, the energy of one of these quartz crystals will aid you. Like Amethyst crystals, it is useful if you have addictions.
It will to help you in letting go of the compulsions associated with them. 
It will clear stress and tension from the head, and will bring excess energy down into the physical for use or release.
Its Citrine energy will enhance your will, and the Amethyst vibration helps you to break self-defeating habits, that may be holding you back. 
Their energy is also said to alleviate depression, anxiety and stress. 
The Citrine Crystal vibration helps you to boost your creativity, and its connection with the crown, the highest chakra in the body may assist psychic artists in their work.

Physical properties of Ametrine

Chemical FormulaSiO2
ColourYellow, Purple, Multicolored
Crystal SystemHexagonal
Refractive Index1.54 - 1.55
SG2.63 - 2.65
Double Refraction.009
Mineral ClassQuartz

Amethyst Gemstone

What is Amethyst?

Amethyst is a violet variety of quartz often used in jewellery. The name comes from the ancient Greek ἀ a- ("not") and μέθυστοςméthystos ("intoxicated"), a reference to the belief that the stone protected its owner from drunkenness. The ancient Greeks wore amethyst and made drinking vessels decorated with it in the belief that it would prevent intoxication. It is one of several forms of quartz. Amethyst is a semiprecious stone and is the traditional birthstone for February.

Amethyst colour

The colour in amethyst from most localities is unevenly distributed in the individual crystals. In amethyst geodes it is often most intense in the growth zones under the rhombohedral faces (at the tips). Occasionally the colour is deeper under either the r or z rhombohedral faces, giving the crystal a pinwheel appearance when viewed from the top. In prismatic crystals the colour may appear in phantom-like thin layers, while in sceptres and skeleton quartz the colour is often concentrated along the edges, and accompanied by smoky zones. Despite the intense colour, the content of iron occupying Si positions in amethyst is rather low, in the 10-100 ppm range.

When heated to more than about 300-400°C, amethyst loses its violet colour and often turns yellow, orange or brown, and then resembles the quartz variety citrine, but depending on the locality and the temperature during the heat treatment it may also turn colourless or rarely green.
Irradiation with UV light will also destroy the colour centres, and accordingly prolonged exposure to sunlight will slowly fade amethyst. The photo to the right shows the effects of heat (bottom left and right) and UV irradiation (top right) on the colour of a specimen from Uruguay.
Amethyst is pleochroic when the polarisation of the light is changed from parallel to the c-axis to perpendicular to the c-axis, amethyst changes its colour from blue-violet to purple. The strength of the effect varies to a considerable degree, and changes in the hue depending on the direction of the transmitted light may be observable with the naked eye, in particular in crystals with a zonar development of colour, which may even show sky-blue tones.

Amethyst Crystals

Amethyst crystals do not get very large, crystals longer than 30 cm are very rare. It is found in various forms and shapes, the most common growth forms are: 
  1. Druzy crystal aggregates that outline cavities; the crystals are usually short-prismatic and often lack prism faces. Most common in volcanic rocks, but also in hydrothermal veins, and even in cavities in sedimentary rocks;
  2. Scepters (late syntaxial overgrowth) on other color varieties of quartz, in particular in high- to medium-temperature environments like alpine-type fissures and pegmatites
  3. Split-growth crystals ("artichoke quartz") in hydrothermal veins in ore deposits, but also in volcanic rocks.
  4. As individual well-formed crystals in small cavities and fissures, in particular in volcanic rocks. 
  5. As hydrothermal vein filling, often with several growth phases with variable color that cause a banding pattern.


Amethyst is produced in abundance from the state of Minas Gerais in Brazil where it occurs in large geodes within volcanic rocks. Many of the hollow agates of southwestern Brazil and Uruguay contain a crop of amethyst crystals in the interior. Artigas, Uruguay and neighbouring Brazilian state Rio Grande do Sul are large world producers exceeding in quantity Minas Gerais, as well as Mato Grosso, Espirito Santo, Bahia, and Ceará states, all amethyst producers of importance in Brazil.
It is also found and mined in South Korea. The largest opencast amethyst vein in the world is in Maissau, Lower Austria. Much fine amethyst comes from Russia, especially from near Mursinka in the Ekaterinburg district, where it occurs in drusy cavities in granitic rocks. Many localities in south India yield amethyst. One of the largest global amethyst producers is Zambia in southern Africa with an annual production of about 1000 tonnes.
Amethyst occurs at many localities in the United States. Among these may be mentioned: the Mazatzal Mountain region in Gila and Maricopa Counties, Arizona; Red Feather Lakes, near Ft Collins, Colorado; Amethyst Mountain, Texas; Yellowstone National Park; Delaware County, Pennsylvania; Haywood County, North Carolina; Deer Hill and Stow, Maine and in the Lake Superior region of Minnesota, Wisconsin and Michigan. Amethyst is relatively common in the Canadian provinces of Ontario and Nova Scotia. The largest amethyst mine in North America is located in Thunder Bay, Ontario.

Amethyst types

Purple Amethyst

Purple Amethyst has been highly esteemed throughout the ages for its stunning beauty and legendary powers to stimulate, and soothe, the mind and emotions. It is a semi-precious stone in today’s classifications, but to the ancients it was a “Gem of Fire,” a Precious Stone worth, at times in history, as much as a Diamond. It has always been associated with February, the month the Romans dedicated to Neptune, their water-god, and is the traditional birthstone of that month. It is the stone of St. Valentine and faithful love, and signifies ecclesiastical dignity as the Bishop’s Stone. It carries the energy of fire and passion, creativity and spirituality, yet bears the logic of temperance and sobriety.

Brandberg Amethyst

Brandberg Amethyst is a unique and extraordinary blend of Amethyst, Clear and Smoky Quartz together in one exceedingly high-vibrational crystal. It is found only in Namibia, Africa, and is imbued with remarkable phantoms, enhydros, and other rare formations and inclusions. It attunes to pure consciousness and is a potent talisman of healing and perfection with the capacity to restore one back to their etheric blueprint in order to realign with the Divine Source.

Chevron Amethyst

Chevron Amethyst displays v-shaped chevrons of deep purple and white Quartz that “seep” into beautiful layers. It is one of the finest Third-Eye stones for stimulating vision within the self as well as the physical world, filtering the life force from the cosmos via the Crown in its white layers and opening up spiritual and psychic channels through the purple. It has a strong, focused energy for dissipating and repelling negativity, and is the perfect crystal for learning any form of spiritual healing. Hold one in each hand for powerful but safe out-of-body travel, shamanic journeying or pathworking, and between the hands while praying or reciting mantras.

Cacoxenite in Amethyst 

Cacoxenite in Amethyst mingles dark brown to yellow tufts of Cacoxenite, a phosphate mineral and major component in the Super Seven crystal, with the host crystal Amethyst. This combination brings a high level of creativity and new ideas to humanity by fostering thoughts that have never been thought of before. It is a calming stone, good in times of upheaval, and raises spiritual awareness of the creator essence in the beauty of nature and the kindness in people. Carry on the night of the crescent and full moon to transfer healing energy to the Earth and create an ethereal connection between all of the universe.

Rutiliated Amethyst

“Rutilated” Amethyst is a rare form of Amethyst which appears to contain Rutile, but actually contains brownish crystals of Goethite, an iron hydroxide mineral also found in the Super Seven crystal. Goethite is a stone for finding the link between the deep self and Earth, and together with Amethyst clears the Earth and Base Chakras, aligning the whole chakra system to the higher mind. It purifies the emotional body and is particularly helpful in grief work. It facilitates clairaudience, communion with angels, and connections with other worlds. To program as a wishing stone or with intentions, messages, and prayers, simply hold the stone with the intent in mind.

Amethyst Healing Properties

Amethyst is a wonderful talisman for use in the creative arts, especially in darker shades. It assists endeavours where new, original results need to be created using tools and methods of the past. It is often used as the Artist’s Stone, the Composer’s Stone, the Inventor’s, Poet’s and Painter’s Stones. Keep an Amethyst crystal or cluster in the area to focus and amplify the creative elements of the Universal Life Force.
Called the “All-healer,” Amethyst is one of the most effective crystals for healing people, plants and animals. Natural unpolished Amethysts or geodes are particularly helpful placed where plants will not grow or animals refuse to sit. It also counteracts negative earth energies beneath buildings or anywhere that feels hostile. 
Amethyst protects against psychic attack, paranormal harm or ill-wishing, and returns the energy back to the universe after being transformed into positive, loving energy. To increase this power and attract good luck, draw an image of the sun and the crescent moon over an Amethyst in lavender incense smoke. 
Referred to as “nature’s tranquilliser,” Amethyst calms and soothes, assisting the transmission of neural signals through the brain. It relieves obsessive compulsive disorder and hyperactivity in children and animals. Place under the pillow or mattress, or rub the centre of the forehead counter-clockwise to cure insomnia and stimulate pleasant dreams. It is especially effective for children’s recurring nightmares and fears of the dark, and may help alleviate homesickness.
Amethyst is an excellent stone for diplomats, negotiators and business people. It calms angry temperaments and gives a distinct advantage in situations where debating is required. Wear or hold Amethyst to bring in spiritual insights coupled with intellectual reasoning. As a luck and prosperity crystal, Amethyst is good for reducing the tendency to overspend, gambling addictions or unwise investments. 
Amethyst is connected to the Temperance card in the tarot, representing balance. It is a stone dedicated to curbing overindulgence and bad habits, and is an excellent aid to quitting smoking, drinking and drug use, as well as unhealthy physical passion. It also provides the strength needed to obtain freedom from addictive personalities, one’s own or another’s. Placing an Amethyst on the navel is believed to protect a person from intoxication, and in conjunction with other treatments such as counselling, helps cure addictions. A naval piercing makes it possible to always keep an Amethyst in this spot. 
Amethyst is the stone of St. Valentine and of faithful lovers because St. Valentine was thought to have worn an Amethyst ring engraved with the image of Cupid. It is also referred to as the “couple’s stone” and gives meaning to relationships that over time, transcends the carnal union and gives way to deeper connection and a more soulful communion. Wear as an engagement or eternity ring for fidelity, or as a locket to call back lost love.

Physical properties of Amethyst

Chemical FormulaSiO2
Crystal SystemHexagonal
Refractive Index1.54 - 1.55
SG2.63 - 2.65
TransparencyTransparent to translucent
Double Refraction.009
Mineral ClassQuartz