Optical Calcite

Physical Information

Optical calcite, also called Iceland spar, is a very clear, colourless variety of calcite (calcium carbonate). It forms rhombohedral crystals that look like slanted cubes, with a glassy lustre. Its most famous feature is double refraction. When you place a clear piece over a line of text, you see the text twice, because the crystal splits light into two rays.

It is found in several places around the world, including Iceland, Mexico and the United States. Iceland gave the stone its old name, and clear pieces were once used in scientific instruments. Calcite is soft, with a hardness of 3 on the Mohs scale, and it breaks easily along flat planes. Handle it gently, keep it away from acids, and dust it with a soft brush or cloth.

Metaphysical Properties

Optical calcite is known as a stone of clarity. It is believed to help people see a situation from more than one side and to bring hidden feelings or ideas to light. Many people also use it to amplify the energy of other crystals and of their own intentions during meditation.

This clear crystal is associated with the crown chakra and the third eye, and with insight, intuition and spiritual growth. Many people keep a piece on their desk when they need a clear head, or place it in a crystal grid to strengthen the energy of the other stones.