1. Color: The most obvious characteristic, but can be misleading as many minerals come in a variety of colors.
2. Streak: The color of the mineral's powder, obtained by rubbing it on a streak plate (unglazed porcelain). This is a more reliable indicator than color alone.
3. Luster: How light reflects off the surface of the mineral, described as metallic, glassy, pearly, dull, etc.
4. Hardness: The mineral's resistance to scratching. This is measured on Mohs Hardness Scale, where 1 is the softest (talc) and 10 is the hardest (diamond).
5. Cleavage/Fracture: How the mineral breaks. Cleavage refers to smooth, flat breaks along planes of weakness in the crystal structure. Fracture refers to irregular breaks.
These five characteristics are often used in combination to accurately identify minerals. Additional characteristics, like density, crystal habit, and specific gravity, can also be helpful.
