Black Mica 10mm Round A Grade - 15-16 Inch 1.7mm Viking explorers used thin pieces

Viking explorers used thin pieces of Iolite as the world’s first polarizing lens to help them determine the exact location of the sun for navigation

Rhodonite belongs to the Pyroxenoid group of minerals

which may form green stains or specks on Azurite crystals or aggregates

We only get the privilege of buying from them once a year so supplies are limited

At that time yellowish gems were called "topaz" in many parts of the world

Black Mica 10mm Round A Grade - 15-16 Inch 1.7mm Viking explorers used thin piecesMica is a mineral name given to a group of minerals that are physically and chemically similar. They are all silicate minerals, known as sheet silicates because they form in distinct layers. Micas are fairly light and relatively soft, and the sheets and flakes of mica are flexible. Mica is heat resistant and does not conduct electricity. There are 37 different mica minerals. The most common include: purple lepidolite, black biotite, brown phlogopite