Home > Burmese Minerals – May 22 > MS1334 Fergusonite-(Y)

Fergusonite-(Y) - Sold

The mineral name fergusonite-(Y) honors Sir Robert Ferguson (1767-1840), landowner, politician, and mineral collector in Scotland (Haidinger, 1825). Ferguson's collection remained intact until 1997, when Brian Lloyd purchased the collection.

Fergusonite-(Y) is nominally a yttrium niobium oxide, but samples typically contain tantalum, other rare earth elements and uranium. In fergusonite-(Y), a minor uranium content causes damage to the atomic arrangement of fergusonite-(Y), leading to a loss of crystallinity. The mineral becomes amorphous in a process known as metamictization. Recognition of fergusonite-(Y) therefore depends on combining chemical analysis with study of its external crystal form.

This specimen is a divergent spray of fergusonite-(Y). The individual crystals are crude tetragonal prisms, many of which showed pointed terminations. The mineral shows superficial brown alteration, itself being resinous black on a fresh surface. There is a bit of adhering clay.