Smoky quartz is a dark variety of quartz(*). It takes its name from its smoky brown color. Like rock crystal, to which it is very similar, smoky quartz is found all over the world. deep brown, almost black-looking stones, which are also known as morions, are considered particularly valuable. However, stones described as morion in the trade are often [...]

The gemstone Tourmaline has been known since ancient times. However, since it has very different external appearances, which all have colors of the rainbow, it was often confused with other stones. The red tourmaline was therefore called "Karfunkel" in the Middle Ages, as was the ruby or garnet. Green tourmalines were also confused with emeralds, [...]

The green color (Greek "malache" = malwe), perhaps also the low hardness (gs. "malakos" = soft) gave the malachite the name. In fracture or ground, aggregates cine banding of lighter and darker layers withconcentric rings, straight stripes or any figurative images due to the skinning structure. Rarely, larger monochrome pieces are obtained. Translucent in thin [...]

Prehnite, also known as aedelite, chiltonite, coupholite and noblerite or under the trade names Cape Chrysolite and Cape Emerald, is a common mineral from the mineral class of "silicates and germanates" with the chemical composition Ca2Al[(OH)2| AlSi3O10]. Prehnite is thus chemically a calcium-aluminum silicate with additional hydroxide ions. The mineral crystallizes in the orthorhommy crystal [...]

Chrysocolla means "gold glue" (girech. chrysos=gold, kolla=glue). However, the exact origin of the name is uncertain. Synonyms for this stone are abundant: Atlas ore, Dillenburgite, Grünspan, Malachite pebble, Resanite. The chrysocollum is always secondary to the action of silica-containing ground water and leachate on copper-containing rock. Like azurite or malachite, it is one of the [...]

Chrysocolla means "gold glue" (girech. chrysos=gold, kolla=glue). However, the exact origin of the name is uncertain. There are many synonyms for this stone: atlas ore, dillenburgite, verdigris, malachite silica, resanite. Chrysocolla is always formed secondarily by the action of siliceous groundwater and seepage water on copper-bearing rock. Like azurite or malachite, it is one of the leading minerals in the oxidation zones of copper ore deposits, i.e. [...]

The gemstone tourmaline has been known since ancient times. However, as it has very different external appearances, all of which have the colors of the rainbow, it was often confused with other stones. The red tourmaline, like the ruby or garnet, was therefore called "carbuncle" in the Middle Ages. Green tourmalines were also confused with emeralds, etc. Its current [...]

The green color (Greek "malache" = malwe), perhaps also the low hardness (gs. "malakos" = soft) gave malachite its name. When broken or polished, aggregates show a banding of light and darker layers with concentric rings, straight stripes or some kind of figurative images, due to the shelly structure. Larger monochrome pieces are rarely obtained. In thin [...]

Prehnite, also known as aedelite, chiltonite, coupholite and edelite or under the trade names cape chrysolite and cape emerald, is a common mineral from the mineral class of "silicates and germanates" with the chemical composition Ca2Al[(OH)2|AlSi3O10]. Chemically speaking, prehnite is therefore a calcium aluminum silicate with additional hydroxide ions. The mineral crystallizes in the orthorhombic crystal system and usually develops tabular to [...]

Emerald is a variety of the silicate mineral beryl, which crystallizes in the hexagonal crystal system and has a Mohs hardness of 7.5 to 8. Its chemistry is described by the composition Al2Be3[Si6O18]. The color is green due to the addition of chromium and vanadium ions, the line color is white. Etymology and history The word "emerald" comes from the Latin smaragdus and from the Greek [...]

Calcite, calcite, calcite spar or double spar, is a very common mineral from the mineral class of "carbonates and nitrates" with the chemical composition Ca[CO3] and thus, chemically speaking, calcium carbonate. Calcite crystallizes in the trigonal crystal system and develops various crystal or aggregate forms (habit). Calcite is colorless and transparent. Multiple refraction of light due to lattice defects or polycrystalline formation can [...]

Lapis lazuli, also known as lapis lazuli or lapis for short, is a naturally occurring, deep blue metamorphic rock which, depending on where it is found, consists of varying proportions of the minerals lazurite, pyrite and calcite as well as smaller amounts of diopside, sodalite and others. Etymology The word lapis comes from the Latin language and means "stone". Lazuli, genitive of the Middle Latin word [...]

Pyrite, also known as sulphur pyrite, iron pyrite, fool's gold or fool's gold, is a very common mineral from the class of "sulphides and sulphosalts". Chemically, it is the cubic modification of iron disulphide with the chemical composition FeS2, i.e. it consists of iron and sulphur in a ratio of 1 : 2. Pyrite is opaque in any form [...]

English: Quartz Siliziumdioxid / Cuarzo / Cuarzo Silicon dioxide (SiO2) = quartz (the; Old Slavic tvrudu, "hard", or Middle High German querch, "dwarf"); mineral occurring as the main constituent in numerous types of rock, made of crystallized anhydrous silicon dioxide, consists of 6-sided regular prisms with attached, regular pyramids when growing freely, belonging to the trigonal class. Quartz is occasionally confused with calcite, but can be distinguished by [...]

Kyanite, also known as cyanite, disthene or sapparite, is a common mineral from the mineral class of "silicates and germanates". It crystallizes in the triclinic crystal system with the chemical composition Al2[O|SiO4], so chemically it is an aluminium silicate. Structurally, it belongs to the island silicates. Kyanite develops predominantly prismatic to tabular crystals with a glass-like luster on the surfaces, occurs [...]

The mineral pyrope (from the Greek pyropos "fiery") is an island silicate from the garnet group and has the chemical composition Mg3Al2[SiO4]3. The mineral crystallizes in the cubic crystal system, often in (rounded) grains. It also occurs in aggregates. Pure pyrope, e.g. from the white slates of the Dora Maira massif, is colorless. Due to the incorporation of iron (Fe2+) instead of magnesium (Mg) [...]

Elkogite is a high-pressure rock mass that forms at a depth of approx. 40 km, mainly in subduction zones, and is up to 3 billion years old. The elkogite from the type locality on the Saualpe is approx. 800 million years old and was south of the equator when it was formed as the northern part of the Gondwana superconinent and is associated with the [...]

Quartz, also known as deep quartz or α-quartz, is a mineral with the chemical composition SiO2 and trigonal symmetry. It is the stable form (modification) of silicon dioxide on the earth's surface and the second most common mineral in the earth's crust after feldspar. At a temperature of more than 573 °C (under a pressure of 1 bar), deep quartz is destroyed by a change in [...]