Biotite is a common mica mineral that is black to brownish-black in color. This soft mineral forms as a “book” with super thin crystal pages. You can use your fingernail to flake apart the individual layers of the book. Each sample comes with an information card. Typical samples sizes are generally 1-2 inches in length or width but can vary based in availability and natural crystal shape.
WARNING: CHOKING HAZARD - Small Parts. Not for Children Under 3 years.