MUSCOVITE
Specimen mus-16
$ 36.00Dims: 6.7 x 3.9 x 3.1" (17.0 x 9.9 x 7.9 cm)
Wt: 2 lbs., 0.5 oz. (920 g)
Minas Gerais, Brazil
Scores of intergrown Muscovite "books" make up this specimen. They achieve maximum dimensions of 1.6 x 1.2 x 0.2" (4.1 x 3.1 x 0.5 cm) and are in fair condition, as many of the exposed blades are damaged or incomplete due to breakage. Those that are intact, however, show very good pseudohexagonal tabular form, with well-defined edges and generally clean faces that possess the standard pearly luster. All have a moderate brown coloration with a hint of red, and only the thinnest of the books are translucent- most are opaque, though individual flakes are transparent. They are attached to a greenish-brown base that sparkles with thousands of tiny, embedded Muscovite platelets. Though it is not evident, I believe that the bulk of this base is made up of a single, large apatite crystal that was coated heavily with the tiny platelets before the larger books formed. There are also many tiny hexagonal apatite prisms partly embedded in and scattered about the formation of larger books. They do not exceed 0.1" (3 mm) along any axis, and have excellent form and an almost vitreous luster. They are also transparent and clear, but have a green color similar to that of the base. There is also a small amount of warped, crystalline albite attached to one end of the base, along with more Muscovite.