From the Greek "Epidosis" = "increase" in allusion to the crystal characteristic of one longer side at the base of the prism.Epidote has a Mohs hardness  of 6 to 7. The color is usually enough to identify epidote. If you find good crystals, they show two strongly different colors (green and brown) as you rotate them. Epidote often represents alteration of the dark mafic minerals in igneous rocks such as olivine, pyroxene, amphiboles and plagioclase. Epidote thus is well known in subducted s...

Rhodium is a member of the platinum metals group. The other members include platinum, palladium, ruthenium, iridium, and osmium.It was first isolated in 1803 by English chemist William Wollaston. Due to the distinctive red color of the dissolved rhodium compounds, Wollaston named the new metal Rhodium based on the Greek word rhodon meaning "rose".Primary sources for rhodium are in Russia, South Africa, and Canada. The industrial extraction of rhodium is complicated by the fact that it occurs nat...

The green chromium-rich variety of muscovite is known as fuchsite. It can have an attractive blue-green to emerald green color that can display a sparkly shine if the crystals are small. Due to its attractive color fuchsite is often used as an ornamental stone. Fuchsite is sometimes confused with Zoisite, since both green minerals can sometimes be found interspersed with ruby. But zoisite is a distinct mineral with a different chemical composition (calcium aluminum silicate). Zoisite is also a m...

Muscovite is a mica found in many types of igneous and metamorphic rocks. It is easily recognized because of its perfect cleavage that allows it to separate into thin, transparent, flexible sheets.Muscovite has a high resistance to heat and, split into thin transparent sheets, it has been used as windows on high-temperature furnaces and ovens. It is an insulator and was used in the past to make circuit boards and as an early window glass. In fact the name muscovite comes from Muscovy-glass, a na...

It was in 1949 when Tom Belvis discovered first the ruby field at Longido in northeast Tanzania.Though the ruby at Longido was found in remarkable quantity much of it was coarse and opaque and encased in a green matrix that turned out to be the mineral zoisite.It took some years before the market could find the best use of this mineral.The combination of the green zoisite with its black streaks of hornblende, and the rich red and pink ruby is unique and attractive. It is one of the most colorful...

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Actinolite is a relatively common mineral in some metamorphic rocks. It is an intermediate member to a series with the minerals tremolite and ferro-actinolite.A variety of actinolite, nephrite, is one of the two minerals called jade. The other jade mineral is jadeite. Notable Occurrences include the Lake Baikal Region, Russia; China; New Zealand; British Columbia, Canada and Taiwan.​

Lovely light pink to dark magenta Cobalto Calcite (AKA Cobalticalcite, Sphaerocobaltite, and Cobaltian Calcite).This is a variety of Calcite containing Cobalt. The result of the cobalt is that the calcite is colored a pale pink. In pure sphaerocobaltite, the coloring effect is magnified.Originally described from Vallone stope, Cape Calamita Mine (Calamita Mine), Capoliveri, Elba Island, Livorno Province, Tuscany, Italy.​

Biotite is a common phyllosilicate mineral within the mica group. Biotite was named by J.F.L. Hausmann in 1847 in honour of the French physicist Jean-Baptiste Biot, who, in 1816, researched the optical properties of mica, discovering many unique properties.Biotite is a sheet silicate. Iron, magnesium, aluminium, silicon, oxygen, and hydrogen form sheets that are weakly bond together by potassium ions. It is sometimes called "iron mica" because it is more iron-rich than phlogopite. It is also som...

Bornite is a copper iron sulfide mineral commonly found in hydrothermal veins, contact metamorphic rocks and in the enriched zone of sulfide copper deposits. It is a common ore of copper and is easily recognized because it tarnishes to iridescent shades of blue, purple, green and yellow. It alters readily upon weathering to chalcocite and other copper minerals. It is often mined as an ore of copper.Typical occurrences are found in Mount Lyell, Tasmania; Chile; Peru; and Butte, Mont., U.S.

Seraphinite is a trade name for a particular type of clinochlore formed from metamorphic and hydrothermal alterations of other iron and magnesium silicate materials. The word Seraph is from Isaiah 6 in the Hebrew Testament, and refers to winged angelic beings in service of God. Seraphinite acquired its name due to its resemblance to feathers, such as one might find on a bird's wing. Color is generally dark green to gray, has chatoyancy, and has hardness between 2 and 4 on the Mohs scale of miner...

Astrophyllite is a very-rare, brown to golden-yellow hydrous potassium iron titanium silicate mineral. Heavy, soft and fragile, astrophyllite typically forms as bladed, radiating stellate aggregates. It is this crystal habit that gives astrophyllite its name, from the Greek words astron meaning "star" and phyllon meaning "leaf". Owing to its limited availability and high cost, astrophyllite is seldom seen in an ornamental capacity. It is sometimes used in jewellery where it is fashioned into ca...

Named after its discovery locality, Mount Vesuvius, Campania, Italy.Brown, yellow, brown-black, light green, emerald green, white, red, purple, violet, blue-green to blueVesuvianite, also known as idocrase is a green, brown, yellow, or blue silicate mineral. Vesuvianite occurs as tetragonal crystals in skarn deposits and limestones that have been subjected to contact metamorphism. It was first discovered within included blocks or adjacent to lavas on Mount Vesuvius, hence its name.

Rock crystal is the name given to all clear colorless quartz.It commonly occurs in quartz veins where it crytallizes inside rock cavities known as vugs. It also is common in vugs or pockets in pegmatite dikes. Rock crystal often occurs as secondary quartz crystals on cryptocrystalline quartz in cavities and vugs, and in geodes. Rock crystal often has minute cavity inclusions containing carbon dioxide or water. If there is a sufficient number of these minute fluid inclusions then the quartz becom...

In many respects stromatolites are the most intriguing fossils. Into deep time on earth, the emergence of life, and the eventual evolving of the beautiful life forms from Cambrian to modern time. A small piece of stromatolite encodes biological activity perhaps spanning thousands of years. In broad terms, stromatolites are fossil evidence of the prokaryotic life that remains today, as it has always been, the preponderance of biomass in the biosphere. For those that subscribe to the theory of the...

Discovered by Obsius in Ethiopia, obsidian is named after him. Obsidian is a rock which is a type of naturally occurring glass, produced by volcanoes (igneous origin) when a felsic lava cools rapidly and freezes without sufficient time for crystal growth (see glass transition temperature). It is commonly found within the margins of felsic lava flows, where cooling is more rapid. Because of the lack of crystal structure, obsidian blade edges can reach almost molecular thinness, leading to its anc...