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Geikielite (original material) - Sold


Geikielite is a nominally a magnesium titanium oxide, isostructural with ilmenite. If the mineral were iron-free, it would be colorless or white. Natural geikielite typically contains iron. Electronic charge transfer between iron and titanium leads to very strong absorption of visible light, which makes it look black. Fletcher (1892) first announced the mineral, naming it after Sir Archibald Geikie (1835-1924), Scottish geologist and Director-General of the Geological Survey of Great Britain. Dick (1893) further described geikielite.

This is a stream worn black mass. It comes in an antique glass vial with three accompanying labels. The earliest label from the British Museum notes "part of the original material brought from Ceylon by Mr. Baddeley. Given by Sir A. Geikie, 1915." A later label from the Philadelphia Academy of Natural Sciences denotes "part of original material". A modern label from Crystal Classics/Kristalle is also present, corroborating these attributions.