A metamorphic rock that forms inside veins of other rocks.

Chemical Formula: Ca2Fe5Si8O22(OH)2
Class: Silicates, Amphibole
Hardness: 5-6
Coloration: Usually a shade of green, but can also be white or violet

How to identify it/Unique Characteristics or Properties: A metamorphic rock that forms inside veins of other rocks. It can form large bands of green rocks often called jade, or needles ranging from large to almost fibrous. Actinolite is the same as tremolite, but contains iron (giving it the green color) instead of tremolite’s magnesium (causing a white color).

Where to find it in…

The Northwest: Alaska’s Kobuk River.
Other: New Zealand, Canada, China.
Past Uses: This has been one of the chief carving minerals all around of the world, from China to South American cultures. Almost every culture that has this mineral has carved in it, since it is hard and stable.
How it was Made: A metamorphic mineral that can form in a wide variety of rocks, including Quartz crystals and often in Calcite.
Interesting Facts: When actinolite is found in large compact quantities, it is called nephrite and is one of two minerals (along with jadeite) we call “jade.” Nephrite is the more common of the two. When actinolite forms inside quartz crystals it creates awesome looking green hairs.