Dickite

This rare specimen features many micro (>1mm) crystallized (??pearlescent, disc-shaped?) dickite crystals (?sprinkled all over quartz druse) (in irregular shapes in a vug in spots on quartz?). Dickite, is a rare aluminum silicate clay mineral belonging to the kaolinite-serpentine group, and have a Mohs hardness of 1.5–2, placing it between talc and gypsum due to its weak hydrogen bonds.. It was named after Allan Brugh Dick, a metallurgical chemist who first described it. While it shares the same chemical composition as kaolinite, nacrite, and halloysite, dickite has a distinct crystal structure, making it a polymorph of these minerals.

Dickite typically forms in hydrothermal systems, shales, and soils, where it serves as an important alteration indicator. It often occurs with other clay minerals and requires X-ray diffraction for positive identification. This specimen would have been tested by Tony Steede most likely at the ROM.