Crystalline System: cubic. Red - violetish: Hardness Density Ref.Index Pyrope Mg3Al2Si3O12 7,25 3,58 g / cm3 1,714 Almandine Fe3Al2Si3O12 7,50 4,32 1,830 Rhodolite Mg,Fe3Al2SiO12 7,25 3,78 - 3,90 1,74-1,78 Orange - yellow-brown : Spessartite Mn3Al2Si3O12 7,25 4,20 - 4,25 1,78 - 1,81 Malaya Mn3Al2(SiO4)3 7,25 3,74 - 4,00 1,78 Hessonite Ca3Al2(SiO4)3 7,25 3,58 - 3,65 1,73 - 1,74 Green : Tsavolite Ca3Al2(SiO4)3 7,25 3,60 - 3,68 1,73 - 1,74 Uvarovite Ca3Cr2Si3O12 7,50 3,85 1,87 Dementoïde Ca3F2SiO12 6,5 - 7 3,82 - 3,85 1,89

In a perfect crystal, when a face appears in crystal in process of growth, all faces appear with same development. If one of symmetrical faces is less developed on a crystalline sample, or exceptionally does not appear, that comes from accidental actions of external environment which opposed its growth. Temperature, pressure, nature of mineral solution, speed of crystalline growth and direction of movement of solution etc... represent external influences on crystalline forms. The frequency of faces of crystals is related to reticular density, fast growth of some faces influences crystalline form definitively. Garnet thus crystallizes under cubic system, whose crystals are characterized by presence of three quaternary axes A4 joining centers of faces, four ternary axes A3 joining opposed tops, six binary axes A2 joining mediums of edges. · One of causes modifying initial form of crystals is truncation. Truncation on corners. Cube Dodecahedron Truncation cuts two different lengths on adjacent corners. Cube Tetrahexahedron Truncation cutting three equal lengths out of three adjacent corners. Cube Octahedron Truncation cuts two equal lengths out of two corners and a larger length on third. Trisoctahedron Octahedron Truncation on segment crosses, two equal lengths out of two corners, a smaller length on third.

Cube Trapesohedron Octahedron Trapesohedron Dodecahedron Trapesohedron Hexoctahedron Dodecahedron Almandine in matrix Pyrope-Almandine Almandine in matrix Almandine in matrix Almandine in matrix Rhodolite (Ambohitompoina) There is also a law according to which certain crystals do not present modifications that on half of corners, or of similar angles. Here is a truncation on a top cutting three different lengths on corners, and which repeats only three times around ternary axis. Cube and diplohedron Diplohedron Right Gyrohedron Left Gyrohedron The diplohedron is made of twenty-four irregular quadrilaterals. The class plagiohedron whose faces (HKL) are arranged in spiral order. In other cases, twelve irregular pentagons are formed by a truncation on one sharp angle, on both adjacent angles, unequal lengths, it is pentagonal dodecahedron. Positive Negative Almandine in matrix Tsavolite (Madagascar) Spessartite in pegmatite (Tsilaizina)