Garnet and determine the composition of garnets in terms of percentages of end-member species within an individual gem. Almandine, sometimes incorrectly called almandite, is the modern gem known as carbuncle (though originally almost any red gemstone was known by this name). The term "carbuncle" is derived from the Latin meaning "live coal" or burning charcoal. The name "Almandine" is a corruption of Alabanda, a region in Asia Minor where these stones were cut in ancient times. Chemically, almandine is an iron-aluminium garnet with the formula FeAl(SiO); the deep red transparent stones are often called precious garnet and are used as gemstones
Moonstone (gemstone) the Florida State Gemstone; it was designated as such in 1970 to commemorate the Moon landings, which took off from Kennedy Space Center. Despite it being the Florida State Gemstone, it does not naturally occur in the state. Moonstone (gemstone) Moonstone is a sodium potassium aluminium silicate ((Na,K)AlSiO) of the feldspar group that displays a pearly and opalescent schiller. An alternative name is "hecatolite". Its name is derived from a visual effect, sheen or schiller (play of color), caused by light diffraction within a micro-structure consisting of regular exsolution layers (lamellae) of different alkali feldspars (orthoclase and sodium-rich plagioclase). Moonstone