Mineral Identification Quiz

1. Which common mineral typically fizzes readily when exposed to a drop of dilute hydrochloric acid?

2. A dark, elongated mineral shows two prominent cleavage directions meeting at roughly 60° and 120°. To which mineral group does it most likely belong?

3. A brassy yellow mineral has metallic luster, a greenish-black streak, and a hardness near 6. Which mineral is it most likely to be?

4. A colorless specimen scratches glass, has no cleavage, and breaks with conchoidal fracture. Which mineral best fits these observations?

5. In mineral identification, what does a streak test reveal?

6. Two mineral samples have the same volume, but one has substantially more mass and feels much heavier. Which diagnostic property differs most directly?

7. A clear mineral has a hardness near 2.5 and three cleavage directions meeting at right angles, producing cube-shaped fragments. Which mineral is the best match?

8. A pale specimen can easily be scratched with a fingernail. Which mineral is the best match?

9. A mineral scratches ordinary glass and is not scratched by a steel nail. What does this most reasonably suggest about its Mohs hardness?

10. A lead-gray, metallic specimen feels unusually heavy and breaks into blocky pieces with three cleavage directions at right angles. What is the best identification?

11. A specimen breaks along curved, shell-like surfaces instead of repeating flat planes. Which property is being observed?

12. A light-colored mineral separates into thin, transparent, flexible sheets that spring back after bending. Which mineral is the best match?

13. A very soft mineral feels greasy or soapy and can be scratched effortlessly with a fingernail. Which mineral is it most likely to be?

14. Two clear specimens are known to be calcite and quartz. Under supervised lab conditions with eye protection, which result would most directly identify the calcite?

15. A black mineral strongly attracts a magnet and leaves a black streak. Which identification is most likely?

16. A mineral may look metallic silver-gray or earthy red, but it consistently leaves a reddish-brown streak. Which mineral is indicated?