Crystal Form: The external shape of a mineral is its crystal form. This shape is determined by the internal arrangement of atoms in the mineral. Crystals can be a variety of shapes, such as cubes, octahedrons, prisms, and pyramids.
Color: The color of a mineral is the most obvious characteristic that mineralogists use to identify them. However, the color of a mineral can vary depending on the impurities that are present.
Luster: The luster of a mineral is the way that it reflects light. Minerals can have a variety of lusters, such as metallic, glassy, dull, and pearly.
Hardness: The hardness of a mineral is its resistance to being scratched. The Mohs scale is a standard used to measure the hardness of minerals. The Mohs scale ranges from 1 (talc) to 10 (diamond).
