Tremolite

Here's a singular gemmy tremolite prism showing very lustrous faces and a nice marbling of green-blue colour. The top is not terminated but cleaved. A very nice sample from the area!

Tremolite from the area is often dubbed "actinolite". Tremolite and actinolite are two very similar minerals that form a series with each other and essentially share the same chemical formula. Tremolite has a greater presence of magnesium over iron, whereas actinolite has a greater presence of iron over magnesium. Analyses have shown that actinolite is very rare and most specimens like this are tremolite.