Which term describes the shine of a mineral?

Which term describes the shine of a mineral?

• A. Streak
• B. Luster
• C. Color
• D. Hardness

Answer: (B)

Luster is the term for how light reflects off a mineral's surface, or its shine. This is the best description for what the question is asking—how the mineral looks when light hits it, which is a direct measure of its surface appearance. Streak describes the color of the mineral’s powder when it’s rubbed on a porcelain plate, a different property altogether. Color is the hue you observe on the mineral’s surface, which can vary due to impurities and isn’t a reliable indicator of shine. Hardness is about how easily the mineral can be scratched, not how it reflects light. Luster can be described as metallic, glassy, dull, pearly, and so on, making it a key way to identify minerals by their shine.

Luster is the term for how light reflects off a mineral's surface, or its shine. This is the best description for what the question is asking—how the mineral looks when light hits it, which is a direct measure of its surface appearance. Streak describes the color of the mineral’s powder when it’s rubbed on a porcelain plate, a different property altogether. Color is the hue you observe on the mineral’s surface, which can vary due to impurities and isn’t a reliable indicator of shine. Hardness is about how easily the mineral can be scratched, not how it reflects light. Luster can be described as metallic, glassy, dull, pearly, and so on, making it a key way to identify minerals by their shine.