Withamite. Glen Coe. Lochaber, Scotland.

This is a thin section of an Andesite from Glen Coe, Lochaber Scotland. Mainly devitrified glass with microlites and flow structure visible. Contains numerous amygdules filled with epidote/zoisite and zeolites. Some of the epidote is a manganese containg variety called Withamite after a Mr Witham who discovered the mineral in Glencoe. It is related to piemontite. The mineral is a vivid orange red and pleochroic with a radiating needle form. Rare and attractive though small.

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