Rare Collectors Gem. Suitable for Museums, Institutions and Students of Gemology. Large Sizes are Rare. Beautiful sharp Cats eye effect. Among the Rarest of gemstones. Rare chance to own a Fine Feldspar Cats eye . Natural gem Free of any Treatment - 100% Natural.
R.I. :1.528 - 1.537 Hardness : 6 Chemical Comp. :Na[AlSi3O8] Density :2.6 - 2.65 Crystal Group :Triclinic
Feldspar comes in white, yellow, or shades of red, orange to brown.Feldspar is a group of minerals related to each other in structure and chemical composition. Feldspar minerals are aluminum silicates of either potassium, sodium, and calcium. Most crystallize in the monoclinic nd triclinic systems. Cleavage is good in 2 directions forming nearly right angled prisms.Feldspar is the name given to a group of minerals distinguished by the presence of alumina and silica (SiO2) in their chemistry. This group includes aluminum silicates of soda, potassium, or lime. It is the single most abundant mineral group on Earth. They account for an estimated 60% of exposed rocks, as well as soils, clays, and other unconsolidated sediments, and are principal components in rock classification schemes. The minerals included in this group are the orthoclase, microcline and plagioclase feldspars. The top states producing feldspar are North Carolina, Virginia, California, Oklahoma, Idaho, Georgia and South Dakota, in descending order of estimated tonnage. Feldspar processors reported co-product recovery of mica and silica sand. Feldspar is mined from large granite bodies (called plutons by geologists), from pegmatites (formed when the last fluid stages of a crystallizing granite becomes concentrated in small liquid and vapor-rich pockets that allow the growth of extremely large crystals), and from sands composed mostly of feldspar. Because feldspar is such a large component of the Earth’s crust, it is assumed that the supply of feldspar is more than adequate to meet demand for a very long time to come. Present mines worldwide are adequately meeting the need for raw feldspar. Rare Collectors Gem.