S&S Geology 2

2. A very light and porous volcanic rock formed when a gas-rich froth of glassy lava solidifies rapidly.
6. An intrusive igneous rock that is black in color and has a composition similar to basalt.
8. A hard, dark, glasslike volcanic rock formed by the rapid solidification of lava without crystallization.
11. A dark, fine-grained volcanic rock that sometimes displays a columnar structure.
12. A sedimentary carbonate rock that contains a high percentage of the mineral CaMg(CO3)2.
14. Coal of a hard variety that contains relatively pure carbon and burns with little flame and smoke.
15. A fine-grained gray, green, or bluish metamorphic rock easily split into smooth, flat pieces.

1. Rock that has formed through the deposition and solidification of sediments.
3. A sedimentary rock formed from rounded gravel and boulder sized clasts cemented together in a matrix.
4. Rock formed by solidification of a molten magma
5. A hard sedimentary rock used as building material and in the making of cement.
7. Rock that was once one form of rock but has changed to another under the influence of heat, pressure, or some other agent without passing through a liquid phase.
9. A bright blue metamorphic rock consisting largely of lazurite, used for decoration and in jewelry.
10. A light-colored igneous rock with grains large enough to be visible with the unaided eye.
13. Fine- to medium-grained, dark gray to black intrusive igneous rock.