A slab of turquoise with pale matrix. It appears to have been cut so as to have a flat face but not to have been polished. This is vintage material and from what I and others can tell is totally natural, with no consolidants, hardeners or enhancement. About 95% of real turquoise is actually treated to make it hard enough to work and polish, and to not absorb skin oils. There are a variety of accepted treatments but I think this is pure rough turquoise. Unfortunately I don't know where this was mined but based on the collection that it came from I'm pretty sure it is from the USA. It is mounted on a black plastic base.
11/16 inch (1.75 cm) wide, 5/16 inch (0.8 cm) deep and 7/16 inch (1.1 cm) tall.