The garnet varieties of species

According to the the Asian Gemmological Association (GIG) local jade research report: purple teeth black primary deposit a variety of mainly produced in many igneous rocks and metamorphic rocks, the majority of gem-quality garnet found in alluvial placer.
Purple teeth black garnet group minerals the complex chemistry silicate minerals (nesosilicate), usually with A3B2 [SiO4] 3. Wherein A represents Ca2 +, Mg2 +, Fe2 +, Mn2 + and other divalent cations, B said Al3 +, Fe3 +, Cr3 + trivalent cations. Crystal morphology of the rhombic dodecahedron, the four corners of octahedral or both poly shape. Aggregate granular or lumpy.
Garnet color influenced by composition effects, showing a variety of colors, including red series includes red ink 'purple' orange; yellow series the yellow 'orange' dense yellow 'brown yellow; green series includes green' olive green 'yellow-green. Crystal surface is glass luster, sub-adamantine luster, fracture significant oil sheen. Transparent to translucent. Homogeneous body does not have multi-color, no birefringence.
Garnet can be divided into two series, six main varieties: the almandine Series (pyrope, almandine, manganese aluminum garnet) and andradite series (uvarovite, calcium aluminum garnet andradite).