Almandine Garnet
The almandine is a variety of garnet being a part of the family of silicates. His coloring is due to the iron.
- Color: red in magenta, magenta dark, purple in purple - brown.
- Hardness: 7 - 7,5
- Refractive index: 1,78 - 1,83
- Density: 3,95 - 4.30
- Chemical composition: Fe3Al2 ( SiO4) 3 (silicate of aluminum and iron)
- Crystalline structure: isometric
- Luster: glassy
- Origin: Germany, Austria, Zimbabwe, Norway, Thailand, Sri Lanka, Canada, India, Madagascar.
Aquamarine
The aquamarine is a variety of beryl being a part of the family of silicates. His coloring matter and the iron.
- Color : Blue, greenish blue.
- Hardness : 7,5
- Refractive index : 1,57 à 1,59
- Density : 2,67 à 2,75
- Cristalline structures : hexagonal
- Luster : glassy
- Chemical composition : Be3Al2 (SiO3) 6 (silicate of aluminium and béryllium)
- Origin : Brazil, Madagascar, Mozambia, Russia, India, Sri Lanka, China.
Amethyst
The amethyst is a variety of quartz. Very estimate being a part of the family of silicates. His tint coloring is due to transfers of load between O2-towards Fe4.
- Colour : purple, purple purple.
- Hardness : 7
- Refractive index : 1,54 à 1,55
- Density : 2,65 à 2,66
- Chemical composition : SiO2 (dioxyde de silicium)
- Crystalline Structure : hexagonal
- Luster : glassy
- Origin : the main deposits are Brazil, Uruguay, Bolivia, Argentina, the United States, east Africa, Zambia, Namibia, Madagascar, India, Sri Lanka, Russia, Australia.
Ametrine
The ametrine is a two-colored variety of quartz compound of amethyst and citrine being a part of the family of silicates.
- Colour : two-colored, purple / yellow.
- Hardness : 7
- Refractive index : 1,54 in 1,55
- Density : 2,65 in 2,66
- Chemical composition : SiO2
- Crystalline Structure : hexagonal
- Luster : glassy
- Origin: Brazil, Bolivia, Uruguay.
Citrine
The citrine is a variety of quartz being a part of the family of silicates. Most of the citrines are warmed amethysts. His yellow color is attributed to the transfers of loads O2-(Ion oxygenates) towards Fe3 + (Ion iron).
- Color : yellow
- Hardness : 7
- Refractive index : 1,54 - 1,55
- Density : 2,65 - 2,66
- Chemical composition : SiO2 (dioxide of silicon)
- Crystalline structure : hexagonal
- Luster : glassy
- Origin : generalized, the best stones come from Brazil.
Green Amethyst
Green Amethyst is a single-crystal variety of always pale green quartz. She is rare in the natural state. The great majority of Prasiolites available on the market are especially quartz irradiated and sometimes warmed amethysts. His coloring is due to the iron.
- Color: pale green, seagreen, green medium, green-yellow, green leek.
- Hardness: 7
- Refractive index: 1,543 - 1,554
- Density: 2,65 - 2,66
- Chemical composition: SiO2 (dioxide of silicon)
- Crystalline structure: hexagonal
- Luster: glassy
- Origin: India, Zimbabwe, South Africa, Germany, Greece and mainly Brazil for the handled prasiolites.
Iolite
The cordierite is a part of the family of silicates. His coloring is due to the presence of irons.
- Color: blue, blue-purple.
- Hardness: 7 - 7,5
- Refractive index: 1,52 - 1,56
- Density: 2,53 - 2,78
- Chemical composition: Mg2Al3 ( AlSi5O18) (alumino-silicate of magnesium)
- Crystalline structure: orthorhombic
- Luster: glassy
- Origin: Brazil, the United States, Canada, Madagascar, Sri Lanka, India, Burma.
Moonstone
The Moonstone is a variety of orthose being a part of the family of feldspars. His optical effects are the adularescence *, the chatoyance *, the asterism *, aventurescence* and opalescence* (*: see glossary).
- Color: colorless, creamy white, grey in silvery, beige in dark brown, light yellow in clear, yellow-orange-colored in orange, brown-orangy color in Orange brownish, salmon pink, Orange reddish, green (rare).
- Hardness: 6 - 6,5
- Refractive index: 1,517 - 1,54
- Density: 2,55 - 2,67
- Chemical composition: K, Na [ AlSi3O8] (Aluminosilicate of potassium and/or sodium)
- Crystalline structure: monoclinic ( orthose ) and/or triclinic (albite, oligoclase)
- Luster: glassy, pearly on the cleavage.
- Origin: Sri Lanka, India, Myanmar, Africa: Tanzania, Madagascar, etc.
Peridot
The peridot belongs to the group of olivines being a part of the family of silicates. His coloring is due to tracks of iron and chromium.
- Color: yellowish green, brownish green
- Hardness: 6,5 - 7
- Refractive index: 1,64 - 1,69
- Density: 3,20 - 3,50
- Chemical composition: (Mg, Fe) [ SiO4]
- Crystalline structure: orthorhombic
- Luster: glassy, fat
- Origin: China, Burma, Pakistan, the United States, east Africa, South Africa, Brazil, Norway, Egypt.
Rock Crystal
The quartz is a part of the family of silicates.
- Color: colorless, yellow greyish / brown ( smoked quartz); light pink ( pink quartz)
- Hardness: 7
- Refractive index: 1,54 - 1,55
- Density: 2,65 - 2,66
- Chemical composition: SiO2 (dioxide of silicon)
- Crystalline structure: hexagonal
- Luster: glassy
- Origin: very wide-spread in the world.
Ruby
The ruby is a variety of corundum being a part of the family of oxides. His coloring is due to the presence of chromium with sometimes tracks of vanadium and of iron.
- Color: red, red-purple
- Hardness: 9
- Refractive index: 1,76 - 1,78
- Density: 3,99 - 4,06
- Chemical composition: Al2O3 ( alumina)
- Crystalline structure: hexagonal
- Luster: glassy
- Origin: Burma, Sri Lanka, Thailand, Cambodia, Vietnam, Madagascar, Tanzania, Kenya.
Sapphire
The sapphire is a variety of corundum being a part of the family of oxides. His coloring is due to the presence of iron and titanium.
- Color: any color
- Hardness: 9
- Refractive index: 1,76 - 1,78
- Density: 3,99 - 4,00
- Chemical composition: Al2O3 ( alumina)
- Crystalline structure: hexagonal
- Luster: glassy
- Origin: Burma, Sri Lanka, India, Madagascar, Kenya, Tanzania, Thailand, Cambodia, China, Australia, the United States.
Sphene / Titanite
The sphene is a part of the family of silicates. His coloring) is due to the iron presence for yellow greenish and of chromium for the intense green.
- Color: yellow greenish, yellow, brown.
- Hardness: 5,5
- Refractive index: 1,84 - 2,11
- Density: 3,45 - 3,55
- Chemical composition: CaTiOSiO4 (silicate of titanium and calcium)
- Crystalline structure: monoclinic
- Luster: adamantine in resinous
- Origin: Madagascar, India, Brazil, the United States, Canada, Pakistan, Russia.
Spinel
The spinelle is a part of the family of oxides. His coloring) going of the greyish blue to the bluish green is due to the presence of iron, the deep blue in the presence of cobalt and the pink in the red in tracks of chromium.
- Color: red, pink, orange, yellow, purple, blue, green, grey.
- Hardness: 8
- Refractive index: 1,71 - 1,92
- Density: 3,60 - 4,00
- Chemical composition: MgAl2O4 (aluminate of magnesium)
- Crystalline structure: isometric
- Luster: glassy
- Origin: Brazil, the United States, Madagascar, Sri Lanka, Burma, the Thailand, the Cambodia, Afghanistan, Russia.
Tourmaline
Tourmalines is varieties of elbaïte of the group of tourmalines being a part of the family of silicates. Only the tourmaline chromifère is a variety of dravite.
- Color: wide color range, green, blue, yellow, pink, red, brown, colorless. Bi-color is common.
- Hardness: 7 - 7,5
- Refractive index: 1,61 - 1,66
- Density: 3.1 - 3.25
- Plural chemical composition: ( NaLiCa) ( Fe11MgMnAl) 3Al6 ((OH) 4 (BO3) 3Si6O18) (tourmaline lithique, magnesian, ferriferous, fluoferrifère, manganésifère, calco magnésifère, calcolithique)
- Crystalline structure: trigonal
- Luster: glassy
- Origin: Brazil, Madagascar, Namibia, Zambia, Sri Lanka, Burma, Russia, the United States, Afghanistan.
Zircon
The zircon is a part of the family of silicates. Blues are obtained almost always by heat treatment. His blue coloring is due to the presence of uranium and its red tint(coloring) by tracks of nobium.
- Color: red, orange, purple, green, blue, yellow, brown
- Hardness: 7,5
- Refractive index: 1,78 - 2,01
- Density: 3,95 - 4,80
- Chemical composition: ZrSiO4 (silicate of zirconium)
- Crystalline structure: quadratic
- Luster: glassy, adamantine, fat
- Origin: Tanzania, Kenya, Madagascar, Cambodia, Sri Lanka, Burma, Thailand, Vietnam, Australia.
