Grossular

Abstract
Grossular (Ca3Al2Si3O12), is a type of garnet mineral that is part of the Ugrandite group. Garnets are neosilicates with the general formula X3Y2(Si O4)3. Within the chemical formula of garnets, the X region is taken up by divalent cations such as Ca, Mg, Fe, or Mn. On the other hand, the Y region is taken up by trivalent cation of either Al, Fe, or Cr. In general, garnet minerals tend to have similar physical properties and crystal form, but differ in chemical composition. As part of the Ugrandite group, grossular has a Ca as the X of the chemical formula and an Al in the Y part of the formula. The elements within garnets form in an octahedral/tetrahedral framework with the SiOoccupying the tetrahedra. In general, garnet minerals tend to come in many different color variations such as red, orange, purple, green, yellow, brown etc, but tend to have a reddish tinge in most samples. Grossular, like other types of garnets, have a reddish shade and are usually found as cinnamon brown, red, or yellow. Similar to many other forms of garnets, grossular has a relatively high Moh's hardness scale of 6.5-7.5. In order to identify the identity of the mystery mineral, physical property test, RAMAN Spectroscopy, and X-ray Powder Refraction were used. The physical property test consisted of 10 tests: cleavage, Moh's hardness, density, crystal habit, magnetism, luster, color, odor, taste, acid reactivity, and streak. That data was then compared to the Dyar and Gunter mineral database in order to identify the mineral. In the RAMAN Spectroscopy and the X-ray Diffraction tests, the data was again compared to a database in order to identify the mineral. The mineral was concluded to be a solid-solution of grossular and another garnet. The industrial uses of garnet were also looked at and an analysis of the economics of the future of the garnet production industry was conducted. 

Mineral Physical Property Tables
Mineral: Thought to be Spessartine