Mica is a healing crystal that has been used for centuries to promote physical, mental, and spiritual well-being. This crystal is thought to be helpful in restoring balance and harmony and is believed to promote feelings of love, peace, and happiness.

Micas have the general formula XY_2-3Z₄O₁₀(OH)₂. Some specific formulas are given in the blue box above. The X atoms are most often K and, less commonly Na or Ca, or rarer elements. If the X atom is K or Na, we call the mica a common mica, if it is Ca (e.g., in margarite), we call the mica a brittle mica.

The identification of a sheet of mica is never much of a problem even for an untrained eye. All forms of mica have perfect basal cleavage, unique hexagonal shaped crystals, and an unmistakable "snap" of cleavage flakes when they are bent together and then released.

U.S. mica price by type 2010-2023 In 2023, the price for one metric ton of dry ground mica in the United States was 300 U.S. dollars.