| 32601: Columbite-(Fe) - $80 IpĂȘ Mine, Golconda Mining District, Governador Valadares, Minas Gerais, Brazil Miniature - 5.0 x 3.9 x 2.6 cm 205 grams Specimen status: Available Send an email with specimen number to order A complete, blocky/tabular,
well-formed and lustrous columbite-(Fe) crystal, fairly
large for the species/locality. Columbite forms a solution
series with tantalite but the end members can be
differentiated by specific gravity. The measured specific
gravity for this sample (5.69) is a much better fit for
the columbite end member (reported specific gravity
5.26-6.5) than for the tantalite end member (reported
specific gravity 6.65-7.95). The specimen shows no tinge
of red color, so it more closely fits columbite-(Fe)
instead of columbite-(Mn). Specific gravity also rules out
tapiolite (reported specific gravity 7.35-7.37), with
which columbite-tantatlite specimens may be misidentified.
Minor muscovite and feldspar. A large specimen for the
species/locality. Self standing and in excellent
condition, Previous dealer label gives a 1951 acquisition
date.
|
|||
|
|||
|