The crystal structure of garnet

garnets is a generic formula X3Y2 (SiO4) 3, silicate minerals (Silicate_minerals).
Garnet necklace
Garnet necklace
X where normally bivalent (divalent) of positive ions (Ca, Mg, Fe) occupy , and Y is where is a trivalent cation (Al, Fe, Cr) occupies , with a regular octahedron or the [SiO4] provided tetrahedral framework. Garnet crystal dodecahedron habit (crystal habit) most commonly found, but there is also a common habit recipe three octahedral (trapezohedron) (note here the "recipe three octahedral " in the main mineral literature will be called kite -shaped three-dimensional geometry THH (Deltoidal icositetrahedron)). They crystallize in the isometric crystal system , there are three equal -length axis and perpendicular to each other . garnet suppliers and will not appear cleavage (Cleavage), so when they burst under pressure will produce significant irregular pieces , a powerful natural crystal energy can bring unlimited inspiration and vitality.
On the market so-called " green garnet Bi " and garnet nothing to do , in fact, prehnite . Prehnite not green garnet , two completely different concepts . The grapes on the market take the side of the stone and green garnet , is nothing more than for financial gain . Value Demantoid very expensive diamond bid , the market is extremely rare.