Amethyst

Amethyst is a violet variety of quartz often used in jewelry. The name comes from the Ancient Greek ἀ a- ("not") and μέθυστος méthystos ("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.

Ammonoidea

Ammonites are an extinct group of marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs are more closely related to living coleoids (i.e., octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living species.

Ammolite

Ammolite General Category fossilized, mineralized Ammonite shell Formula (repeating unit) CaCO 3 aragonite polymorph, with minor amounts of calcite, pyrite, silica, and other impurities Identification Color Cleavage no true cleavage Mohs scale hardness 4.5 - 5.5 Polish luster Optical properties Ammolite is an opal-like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of North America.

Arctinurus

Arctinurus boltoni is a large (up to 30 cm) lichid trilobite of the mid- Silurian. This trilobite reached about eight inches in length, though the normal adult carapace was about four inches. It lived in moderately deep-water in semi-tropical regions. Arctinurus fossils have been found in Europe and North America.

Azurite

Azurite General Category Carbonate mineral Formula (repeating unit) Cu 3(CO 3) 2(OH) 2 Unit cell a = 5.01 Å, b = 5.85 Å, c = 10.35 Å; β = 92.43°; Z=2 Identification Color Azure-blue, Berlin blue, very dark to pale blue; pale blue in transmitted light Twinning Rare, twin planes {101}, {102} or {001} Tenacity brittle Optical properties Biaxial (+) Refractive index n α = 1.730 n β = 1.758 n γ = 1.838 References [1] [2] [3] Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits.

Beryl

"Beril" and "Heliodor" redirect here. For the character in Tolkien's legendarium, see House of Bëor. For the given names, see Beryl (given name) or Heliodorus (given name). For the Sailor Moon villain, see Queen Beryl. For other uses, see Beryl (disambiguation).

Brachyphyllum - Wikipedia, the free encyclopedia

Brachyphyllum is an extinct genus of plants belonging to Araucariaceae. They were found around the globe during the Carboniferous to the Cretaceous period.

Calcite

Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate ( Ca C O 3). The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470 °C, and vaterite is even less stable. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals.

Celestine (mineral) - Wikipedia, the free encyclopedia

Celestine or celestite ( Sr S O 4) is a mineral consisting of strontium sulfate. The mineral is named for its occasional delicate blue color. Celestine is the principal source of the element strontium, commonly used in fireworks and in various metal alloys.

Chambersite - Wikipedia, the free encyclopedia

Chambersite is a manganese borate mineral with formula:Mn 3B 7O 13Cl. It is a member of the borate mineral series that includes other minerals such as ericacite, Fe 3B 7O 13Cl, and boracite Mg 3B 7O 13Cl. When chambersite was first discovered, it was the second chemical analogue of boracite to be found in nature.

Chrysocolla - Wikipedia, the free encyclopedia

Concretion - Wikipedia, the free encyclopedia

A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word 'concretion' is derived from the Latin con meaning 'together' and crescere meaning 'to grow'.

Crinoid

Crinoids are marine animals that make up the class Crinoidea of the echinoderms (phylum Echinodermata). Crinoidea comes from the Greek word krinon, "a lily", and eidos, "form". They live both in shallow water and in depths as great as 6,000 metres (20,000 ft).[citation needed ] Sea lilies refer to the crinoids which, in their adult form, are attached to the sea bottom by a stalk.

Dioptase

Dioptase is an intense emerald-green to bluish-green copper cyclosilicate mineral. It is transparent to translucent. Its luster is vitreous to sub- adamantine. Its formula is CuSiO 3·H 2O (also reported as CuSiO 2(OH) 2). It has a hardness of 5, the same as tooth enamel.

Echinoderm - Wikipedia, the free encyclopedia

Echinoderm is the common name given to any member of the Phylum Echinodermata (from Ancient Greek, ἐχῖνος, echinos - "hedgehog" and δέρμα, derma - "skin") of marine animals. The adults are recognizable by their (usually five-point) radial symmetry, and include such well-known animals as starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies".

Emerald

Emerald is a gemstone and a variety of the mineral beryl (Be 3Al 2(SiO 3) 6) colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5-8 on the Mohs scale. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor.

Fluorite

Fluorite General Category Halide mineral Formula (repeating unit) CaF 2 Crystal symmetry Isometric H-M Symbol 4/m 3 2/m Unit cell a = 5.4626 Å; Z=4 Identification Color Colorless; although samples are often deeply colored owing to impurities. Crystal system Isometric, cF12, SpaceGroup Fm3m, No.

Fossil - Wikipedia, the free encyclopedia

Fossils (from Classical Latin fossilis; literally, "obtained by digging") are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers ( strata) is known as the fossil record.

Gemstone

"Precious Stone" redirects here. For the James Bond character, see Hurricane Gold. A gemstone or gem (also called a fine gem, jewel, or a precious or semi-precious stone) is a piece of mineral crystal, which, in cut and polished form, is used to make jewelry or other adornments.

Geode

Not to be confused with geoid. Geodes ( Greek γεώδης - ge-ōdēs, "earthlike") are geological secondary structures which occur in certain sedimentary and volcanic rocks. They are themselves of sedimentary origin formed by chemical precipitation.

Glossopteris

Glossopteris ( Ancient Greek: γλώσσα glossa, meaning "tongue", because the leaves were tongue-shaped) is the largest and best-known genus of the extinct order of seed ferns known as Glossopteridales (or in some cases as Arberiales or Dictyopteridiales). The Glossopteridales arose in the Southern Hemisphere around the beginning of the Permian Period ().

Gold - Wikipedia, the free encyclopedia

Gold is a chemical element with symbol Au (from Latin: aurum) and atomic number 79. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable and ductile metal. Chemically, gold is a transition metal and a group 11 element.

Grandidierite - Wikipedia, the free encyclopedia

Grandidierite is an extremely rare mineral and gem that was first discovered in 1902 in southern Madagascar. The mineral was named in honor of French explorer Alfred Grandidier (1836-1912) who studied the natural history of Madagascar.

Gypsum

Gypsum General Category Sulfate minerals Formula (repeating unit) CaSO 4·2H 2 O Identification Color Colorless to white; may be yellow, tan, blue, pink, brown, reddish brown or gray due to impurities Tenacity Flexible, inelastic.

Hibonite

Hibonite Hibonite, 1.6 cm sharp and lustrous crystal from Esiva eluvials, Maromby Commune, Amboasary District, Anosy (Fort Dauphin) Region, Tuléar (Toliara) Province, Madagascar General Category Oxide minerals Formula (repeating unit) (Ca,Ce)(Al,Ti,Mg) 12O 19 Crystal symmetry Hexagonal dihexagonal dipyramidal H-M symbol: (6/m 2/m 2/m) Space group: P 6 3/mmc Identification Color

Jeremejevite - Wikipedia, the free encyclopedia

Jeremjevite colorless to light blue crystal spray of prisms from Ochtendung, Eifel, Germany

Keichousaurus

Keichousaurus is a genus of marine reptile in the pachypleurosaur family which went extinct at the close of the Triassic in the Triassic-Jurassic extinction event. The name derives from Kweichow (now Guizhou Province) in China where the first fossil specimen was discovered in 1957.

Malachite

Malachite is a copper carbonate hydroxide mineral, with the formula Cu 2 (OH) 2. This opaque, green banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures and spaces, deep underground, where the water table and hydrothermal fluids provide the means for chemical precipitation.

Mineral

A mineral is a naturally occurring substance, representable by a chemical formula, that is usually solid and inorganic, and has a crystal structure. It is different from a rock, which can be an aggregate of minerals or non-minerals and does not have a specific chemical composition.

Neuropteris

From Wikipedia, the free encyclopedia Neuropteris is an extinct seed fern that existed in the Carboniferous period, known only from fossils. Major species include Neuropteris loschi. It is a fairly common fossil in bituminous coal with Alethopteris and similar ferns, especially in the Carboniferous Alleghany Mountains of Pennsylvania, they can be found near St.

Opal

Opal General Category Mineraloid Formula (repeating unit) Hydrated silica.

Orthoceras

Orthoceras ("straight horn") is a genus of extinct nautiloid cephalopod. This genus is sometimes called Orthoceratites. Note it is sometimes misspelled as Orthocera, Orthocerus or Orthoceros ( Sweet 1964:K222). Orthoceras fossils are common and have a global distribution, occurring in any marine rock, especially in limestone.

Orbicular jasper - Wikipedia, the free encyclopedia

Orbicular jasper is a variety of jasper which contains variably-colored orbs or spherical inclusions or zones. In highly silicified rhyolite or tuff, quartz and feldspar crystallize in radial aggregates of needle-like crystals which provide the basis or seed for the orbicular structure seen in this kind of jasper.

Pallasite

A pallasite is a class of stony-iron meteorite. It consists of centimeter-sized olivine crystals of peridot quality in an iron- nickel matrix. Coarser metal areas develop Widmanstätten patterns upon etching. Minor constituents are schreibersite, troilite, chromite, pyroxenes, and phosphates ( whitlockite, stanfieldite, farringtonite, and merrillite).

Petrified wood - Wikipedia, the free encyclopedia

Petrified wood is a fossil in which the organic remains have been replaced by minerals in the slow process of being replaced with stone. This petrification process generally results in a quartz chalcedony mineralization. Special rare conditions must be met in order for the fallen stem to be transformed into fossil wood or petrified wood.

Pyrite

This article is about iron pyrite. For other pyrite minerals, see Pyrite group. The mineral pyrite, or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S 2. This mineral's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold.

Quartz

Quartz is the second most abundant mineral in the Earth's continental crust, after feldspar. Its crystal structure is a continuous framework of SiO 4 silicon- oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of . There are many different varieties of quartz, several of which are semi-precious gemstones.

Ruby

A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum ( aluminium oxide). The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires.

Scolecite

Scolecite General Category Zeolites Formula (repeating unit) CaAl 2Si 3O 10·3H 2 O Dana classification 77.1.5.5 Identification Color Colorless white, pink, salmon, red or green Twinning Common on {100}, twin axis [001], rare on {001} and {110} Cleavage Perfect on {110} and {110} Tenacity Brittle Optical properties Biaxial (-) Refractive index N x = 1.507 to 1.513 N y = 1.516 to 1.520 N z = 1.517 to 1.521 Pleochroism X: colourless Y: colourless Z: colourless Other characteristics Pyroelectric and piezoelectric, sometimes fluorescent yellow to brown in LW and SW UV.

Sphalerite

Sphalerite General Category Sulfide mineral Formula (repeating unit) (Zn,Fe)S Dana classification 02.08.02.01 Identification Color Brown, yellow, red, green, black. Crystal system Isometric hextetrahedral (4 3m) Optical properties Isotropic Refractive index n α = 2.369 Other characteristics non-radioactive, non-magnetic, fluorescent and triboluminescent.

Stibnite

Stibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb 2 S 3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony. The name is from the Greek στίβι through the Latin stibium as the old name for the mineral and the element antimony.

Taaffeite - Wikipedia, the free encyclopedia

Taaffeite (; BeMgAl 4O 8) is a mineral, named after its discoverer Richard Taaffe (1898-1967) who found the first sample, a cut and polished gem, in October 1945 in a jeweler's shop in Dublin, Ireland. As such, it is the only gemstone to have been initially identified from a faceted stone.

Tetrahedrite - Wikipedia, the free encyclopedia

Tetrahedrite is a copper antimony sulfosalt mineral with formula: . It is the antimony endmember of the continuous solid solution series with arsenic-bearing tennantite. Pure endmembers of the series are seldom if ever seen in nature. Of the two, the antimony rich phase is more common.

Tourmaline - Wikipedia, the free encyclopedia

Tourmaline ( ) is a crystalline boron silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is classified as a semi-precious stone and the gemstone comes in a wide variety of colors. The name comes from the Tamil and Sinhalese word "Turmali" (තුරමලි) or "Thoramalli" (තෝරමල්ලි), which applied to different gemstones found in Sri Lanka.

Trilobite

Trilobites (, ; meaning "three lobes") are a fossil group of extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest known groups of arthropods.

Turquoise

Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminium, with the chemical formula Cu Al 6() 4( OH) 8·4. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue.

Ulexite

Ulexite General Category Nesoborates Formula (repeating unit) NaCaB 5O 6(OH) 6*5(H 2 O) Dana classification 26.05.11.01 Crystal symmetry Triclinic 1 pinacoidal Identification Color Colorless to white Crystal system Triclinic Cleavage Perfect on {010} good on {110} poor on {110} Tenacity Brittle Optical properties Biaxial (+) Refractive index n α =

Vanadinite

Vanadinite General Category Vanadate mineral Apatite group Formula (repeating unit) Pb 5(VO 4) 3 Cl Unit cell a = 10.3174 Å, c = 7.3378 Å, Z=2 Identification Colour Bright red, orange-red, red-brown, brown, yellow, grey or colourless, may be concentrically zoned Crystal system Hexagonal dipyramidal 6/m Fracture Uneven to conchoidal