Madagascar corundums ( Sapphire & Ruby discovery )

Written by Alain Darbellay GGGems


Continued from page 1
Ruby in amphibolite. The crystals engaged in rocks, rich in mica have rough faces, encrusted of biotite or muscovite, minerals which also exist atrepparttar state of inclusions, associated with magnetite and pyrite. Because of its hardness, its inalterability and its density, corundum constitutes a standard mineral of alluvia. Ruby Giant Sapphire in a metamorphic dolomitic limestone. Polychrome Sapphire Blue Sapphire ( origin: Blue Sapphire ( origin: Ilakaka 1999 ) ( origin: Iankaroka 1990 ) Andranondambo 1992 ) Found inrepparttar 109296 sandstones of Isalo in This sapphire comes from a granit, The stone comes from alluvium,repparttar 109297 shape is rounded. its shape is intact. a metamorphized limestone. The origin ofrepparttar 109298 stone is a limestone. ∑ The structure of crystals. It is R.J.HaŁy who put forthrepparttar 109299 first assumption, confirmed 200 years later, onrepparttar 109300 structure ofrepparttar 109301 crystallized material. He lets drop accidentally a calcite crystal which broke into small rhomboedrons. He supposed whereas repparttar 109302 crystals were consisted of stacking small rhomboedrons elementary (that he calledrepparttar 109303 "integral molecule"), he could reconstitute all known shapes of calcite. In a crystal lattice, three atoms or groups of atoms (nodes), which is not onrepparttar 109304 same line, determine a plan called reticular plan. But there is a great number of these plans: it is enough to choose nodes not strictly nearby. Asrepparttar 109305 network is infinite, there is even an infinity of possible plans. The dimension ofrepparttar 109306 faces does not play of role. Inrepparttar 109307 course of growth, a face can develop more quickly than another. The angle thatrepparttar 109308 faces make between them remains constant, since it depend onrepparttar 109309 network. This structure ofrepparttar 109310 crystalline material explainsrepparttar 109311 law ofrepparttar 109312 constancy ofrepparttar 109313 dihedral angles. Triangular figure on a Scratches on a rare Stacking in macle Triangles on a translucent colorless corundum. colorless corundum. of a ruby. corundum. Triangular figure on a Triangles in step on a blue Remarkable macle of blue corundum. corundum from Maromby. red corundum. Sapphire & Ruby Safari Gem ruby from Ambatovaravarana. The alluvial ruby deposit of Ambatovaravarana inrepparttar 109314 high plateaus, is inrepparttar 109315 left center onrepparttar 109316 picture, underrepparttar 109317 hill.

Macle of blue sapphire. Macle of ruby 60 grms. Information ¶ Cutting Styles ¶ Characteristics ¶ Crystalline Systems ¶ Madagascar Sapphire Andranondambo Sapphires ¶ Blue Sapphire Crystal ¶ Ruby Crystal ¶ Sapphire Slice Your guide to GGGems.com Allrepparttar 109318 pictures on this site have been shot by gggems.com Alain Darbellay

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Madagascar Amethyst

Written by Alain Darbellay GGGems


Continued from page 1
Certain minerals present sometimes left forms sometimes right forms. The most known example is that of quartz. The distinction between left quartz and right quartz has a certain importance inrepparttar electronics industry where one usesrepparttar 109295 piezo-electric properties of this mineral. The negative crystals of hexagonal shape can contain liquids like water, gas, as well as rutile needles, tiny hematite discs, goetite, fushsite or mica. Inclusions of H2O and CO2 in an amethyst from Madagascar. Habitus type of flattened Dauphinť. This marvellous Bi-terminated amethyst of 128 grams also contains water drops in its center. Habitus type of rhomboedron. Enlarge The amethyst scepters are also typical in Madagascar. Here, a scepter inrepparttar 109296 blackberry shape. There,repparttar 109297 stem ofrepparttar 109298 scepter developed by crystallizing around it a quantity of small points in hedgehog. Length:40 mm. Double scepter. Enlarge Head of scepter: 132 grams Enlarge Amethyst in castle on its quartz gangue. 986 grams. Enlarge The fact that sometimes only a thin surface layer of violet color be presents inrepparttar 109299 stone or that this color is not homogeneous, makes often a difficult cutting. The art of lapidary is to placerepparttar 109300 color correctly in order to make homogeneousrepparttar 109301 tone ofrepparttar 109302 cut stone. The distribution ofrepparttar 109303 color in a cut stone is observed simply by immersing it in water contained in a transparent container and colourless. The color of amethyst varies from purple reddish to purple bluish while passing by straightforwardly crimsons tone. Thus of very variable intensity,repparttar 109304 color is often laid out in stripes parallel torepparttar 109305 final faces ofrepparttar 109306 crystal.

Enlarge ¶ Cutting Styles ¶ Characteristics ¶ Crystalline Systems ¶ ¶ Amethyst Crystal 1 ¶ Amethyst Crystal 2 ¶ Amethyst Scepter ¶ Faceted Amethyst ¶

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