Silicate minerals
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Silicates comprise about a quarter of the known minerals and almost 40% of the common ones. The basic unit of structure of all silicate crystals is the tetrahedron. There are four oxygen atoms, one located at each apex of a regular tetrahedron.
The Silicates. Nearly all of the remaining precious stones belong to a great group of mineral species known as the silicates. These are so called because they consist largely of oxide of silicon (the material above referred to under quartz gems).
Silicates (zeolites)
Analcime, Chabazite, Epistilbite, Levyne, Mesolite, Natrolite, Laumontite, Thomsonite, Stilbite.
left - A large boulder, rich in small vesicles, cracked open to reveal a much larger, zeolite-filled cavity.
silica
Silica is a very common mineral composed of silicon and oxygen (SiO2). Silicates make up about 95% of the Earth's crust.
Silica: Crystalline silica is the scientific name for a group of minerals composed of silicon and oxygen. The term crystalline refers to the fact that the oxygen and silicon atoms are arranged in a three-dimensional repeating pattern.
Silicate: Any of a large group of minerals, forming over 90 percent of the earth's crust, that consist of silicon, oxygen, and one or more metals, (and sometimes hydrogen).
Silica - an abundant mineral, and a main component of dinnerware and glazes.
Silicates: Regardless of what other atoms are present (usually one or more metals), gems of this category will have in their chemical formulas some number of Si and O (silicon and oxygen) atoms listed together as a group .
Silica - Silicon dioxide, SiO2.
Silver - A fairly soft (2.5-3), very heavy (density 10.5), ductile and malleable metal. It is the best known conductor of heat and electricity.
Calsilica
Rainbow calsilica is a newly-found, multi-colored, layered stone composed of calcium and silica. This stone has been recently used for Zuni fetish carvings and in some jewelry (beads and cabochon cut stones).
The Silicate Minerals
The great majority of rocks are made of silicate minerals.
Sulfate Minerals
Sulfate minerals form near the Earth's surface.
Silicates
Top
The fundamental constituent of the minerals of the silicate class is the silicate radical (SiO4)4-. This anion group is composed of one silicon atom bonded to four oxygen atoms, which occupy the apices of a regular tetrahedron.
Silicates
Chemistry:
Ca3Al2(SiO4)3 Calcium aluminum silicate (Hessonite contains some iron) ...
SilicateAntigorite
Mg3Si2O5(OH)4
Other names/forms:
Serpentine
Most distinguishing features:
Lustre, colour and habit are indicative.
Silicate Glassy or stony component made up primarily of the element silicon
Strewnfield The area over which a meteorite has fallen
Sulfide Sulfur-containing, as in sulfur-oxide ...
A silicate of zirconium, this mineral occurs in different colours or may be colourless, the latter often being referred to as the poor man's diamond. In fact, zircon tends to be rather dim and is only used for inexpensive jewelry.
A silicate of alumina, iron, and magnesia having a bright blue color and vitreous luster.
Iridescence
Reflection of light off internal features in a gem, giving rise to a rainbow like play of colors.
Calsilica: This is a newly found multi-layered stone used for beads and carvings. Often called rainbow calsilica it is comprised of calcium and silica.
Copper silicate ore.
Chrysorin
Loose term covering cold working brass with 72-66% copper and 28-34% zinc ...
Silicates. This group of minerals contains SiO44- as the dominant polyanion. In these minerals the Si4+ cation is always surrounded by 4 oxygens in the form of a tetrahedron.
Zirconium Silicate ZrSiO4*
Hardness
7 to 7.5 variable, even within a single specimen. "Low" types 6.5 ...
Topaz is a silicate or "nesosilicate" mineral created from a combination of aluminium and fluorine. It crystallizes in the orthorhombic system and it's crystals are prismatic in form.
Absolute Hardness: 200 ...
Rainbow Calsilica
Avoid chemicals, rough handling, and excessive heat.
None ...
Beryl is a silicate mineral group with several varieties of gemstones, including well-known gems like emerald, aquamarine, and morganite, as well as more exotic gems like bixbite, heliodor, and goshenite.
Fine grained silicate rock produced by metamorphism.
MC -
Miarolitic cavities.
Zircon (zircon silicate) is a lustrous gemstone that comes in colors ranging from golden brown to red to violet to blue. Pure zircon is colorless, but most zircon stones are brown.
It is aluminum silicate having the chemical formula Al2 SiO5.
Colours
Different shades of brown and green. Other colours are red, gray, orange and pink.
Epidote: A silicate of alumina, lime, and oxide of iron, or manganese. It is commonly of a yellowish green (pistachio) color.
Essex crystal: See Reverse Crystal jewelry.
Magma...Molten silica containing volatile substances in solution, present beneath the surface in certain areas of the earth's crust.
Malleable...Can be flattened by pounding, as in metals.
Mammillary... rounded mineral surface ...
ring silicates Same as cyclosilicates - Group of silicate minerals that have their tetrahedrons linked into rings. Each silicon atom is bound by two oxygen atoms that are part of another tetrahedron.
GEM SILICA Quantum Four - rare. Enhanced communication, connection with goddess energies, clairvoyance, joy and peace. Premier stone for opening and empowering the throat chakra ...
Quantum-Quattro Silica ™ contains bright medium blues, dark royal blues, dark forest and light greens.
Topaz (aluminum silicate fluoride hydroxide) is a very hard gemstone that ranges in color from brown, to yellow to blue to pink. Pink topaz is usually created by irradiating common yellow topaz.
Psilomelane is silicated manganese ore. It has silver lines on a black background and often clear, or Drusy Chalcedony. Psilomelane is pronounced sill-ahm-ah-lane. Sometimes spelled Psillmelane.
...
ZrSiO4, Zirconium Silicate. Zircon is not the same material as the artificial gem material Cubic Zirconia (or CZ). Zircon resembles diamond in luster and fire and colorless zircons have been mistaken for diamonds by experienced jewelers.
A calcium aluminum silicate Ca2Al3(O/OH/SiO4/Si2O7) by chemical composition, tanzanite belongs to the zoisite mineral family. It has a hardness of 6.
Zircon is zirconium silicate, ZrSiO4, and is notable as a gem mineral for its high R.I., high dispersion, and subadamantine luster.
It is essentially a silicate of alumina and soda. Scapolite is also called Wernerite, named after the German Geologist A.G. Werner. Scapolite is typically an altered form of plagioclase feldspars found in metamorphic rocks.
Topaz is an alumina silicate with a hardness of 8 on the Mohs scale, making it one of the harder gems - but it shares the quality of cleavage with its cousin the diamond.
Beryllium-aluminium-silicate or Beryl is widely used as a gem material. In its pure form (also known as Goshenite), beryl is colourless. However, stored foreign substances give it different colours and different names.
RELATED TERMS: See Link, Bead, Figaro, Wheat, Curb, Perfectina, Rolo, Espiga, Raso, Singapore, Mariner, Cable, Bike Link, Open Link, Omega, Rope, Snake and Box Chains Chalcedony:A subgroup of quartz composed of silica with minute crystals of ...
Most obsidian is 70 percent silica. Obsidian has a hardness of 5 and a specific gravity of 2.35. The pin above is mahogany (brown) obsidian.
Garnets are any of a group of semi-precious silicate stones that range in color from red to green (garnets occur in all colors but blue).
A white or grey mineral composed of Calcium Boro-silicate Hydroxide. Howlite is easily dyed various colors and with its attractive grey matrix, is often dyed azure blue and used as a turquoise look-alike. Howlite has a hardness of 3.5.
Iolite ...
2, Chain Silicates. John Wiley and Sons, New York.
DelRe N. (1992) Gem Trade Lab notes: Repaired jadeite. Gems & Gemology, Vol. 28, No. 3, pp. 193-194.
Ehrmann M.L. (1958) A new look in jade. Gems & Gemology, Vol. 9, No. 5, pp.
Remember that quartz, with a hardness of 7, is one of the most abundant minerals on earth, in the form of sand, or silica. When removing dust from soft stones, it's usually best to rinse them with clean water and dry with a soft cloth.
Topaz (aluminum fluorite silicate) is the hardest of the silicate minerals, due to strong chemical bonds within the stone.
This olivine variety is composed of magnesium iron silicate. Peridot (pronounced PEAR-ih-doh or PEAR-ih-dot) is created under great temperatures and pressures deep within the Earth, and sometimes is extruded in basaltic lavas.
Opal is thought to form over hundreds to millions of years, after water percolates through silica-rich rock, drawing out minerals.
Onyx is formed by the deposition of silica in gas cavities in lava, which results in the distinctive bands. Onyx registers the gravitational pull of Earth. It therefore is grounding, aids concentration, and absorbs negativity from the environment.
Silicates - Mineral containing silicon and oxygen, along with other elements.
Skarn - A contact metamorphic rock, often containing well-formed crystals of silicate and other minerals.
Amethyst is the most highly prized variety of quartz, and is formed in silica-rich liquids deposited in lava gas cavities, called geodes. Though geodes are the best place to located amethysts, they also sometimes grow as stalactites.
From a chemical-mineralogical point of view, emeralds are beryllium-aluminium-silicates with a good hardness of 7.
Garnet: A family of stones having many varieties differing in color and in their constituents, but all are silicates with the same isometric crystallization and conforming to the same general chemical formula.
Tanzanite is the gem name for the silicate mineral Zoisite. Although this fairly common mineral has long been known to geologitsts, the gem form of this mineral was only discovered in 1967.
Topaz is the hardest of all silicate minerals. It does posses a very strong cleavage, which makes cutting and handling a challenge. As a result, it can be split with a single blow, a trait it shares with diamond.
The lithium in kunzite’s chemical composition, lithium aluminum silicate, along with trace amounts of manganese, gives it the wonderful pink colors that complement both autumn and spring wardrobes.
(This is the last edition of Dana that included silicates. Dana's 7th edition never was completed and is divided into 3 volumes making it more difficult to use.
Sillimanite (aluminum silicate, Al2 SiO5) is a transparent to translucent mineral that ranges in color from white to gray to brownish to greenish.
 See also: Stone, Crystal, Color, Mineral, Gemstone
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