Blue streak

Blue streak

There are a few minerals that have a bright blue streak. Linarite often forms as a crust of tiny crystals on other minerals. It has an intense blue colour and a bright blue streak.

Azurite and lazurite have blue streaks - both have been powdered and used to make blue paints. Lazurite is usually found combined with other minerals to form the semi-precious stone called lapis lazuli.