2.  Mineral composition  Color  Texture

3.  Made from mixtures of minerals and other materials.  Rock-forming minerals  Contain several minerals (ex. Quartz, feldspar, hornblende, and mica)

4.  Provides clues to the rock’s mineral composition  Example: granite is light-colored that has a high silica content.  Silica- used in glassmaking activities and hydraulic fracturing

6.  Grains  Tiny particles of minerals stuck together.  Size ▪ larger grains = more coarse ▪ Smaller grains= fine

8. GRAIN SHAPE  Smooth vs. Jagged  Depends of composition of rock

9. GRAIN PATTERN  Flat layers vs. Swirling