Small amounts of books of amber sheet-mica, up to 20 centimetres across, have been observed in pegmatites on Mount Griffin, located about 26 kilometres west of Revelstoke. The mica is fractured and twinned and contains inclusions.

Surrounding rocks comprise Precambrian-Paleozoic(?) Shuswap Metamorphic Complex granitic gneiss, paragneiss, garnet sillimanite schist, amphibolite, marble, orthogneiss and quartzite.