Basaltic – dense, dark- Colored igneous rock formed from magma

Cementation – when sediments are glued “cemented” together

Cleavage – physical property of some minerals that makes them break along smooth, flat surfaces

Color – the hue, shade, or pigment of a mineral

Compaction – when sedimentary rocks are compressed by the layers above them

Extrusive – fine-grained igneous rock that forms when magma cools at or near earth’s surface

Foliated – metamorphic rock which are folded and flattened into parallel layers

Fracture – physical property of minerals that break with uneven, rough, or jagged surfaces

Granitic – light-colored silica-rich igneous rock (less dense than basaltic)

Hardness – measure of how easily a mineral can be scratched.

Igneous – rock formed when magma or lava cools and hardens

Intrusive – igneous rock with large crystals formed when magma cools below earth’s surface

Lava – molten rock that flows from volcanoes onto earth’s surface

Luster – the way a mineral reflects light (metallic or non-metallic)

Metamorphic – forms from heat & pressure (changes a rock’s form &/or composition)

Minerals – naturally occurring, inorganic solid w/definite chemical composition

Moh – moh’s scale is used to measure the hardness of a mineral

Nonfoliated – metamorphic rock where grains are rearranged but don’t form layers

Rock – mixture of minerals, rock fragments, or organic matter

Rock cycle – describes how rocks change slowly from one type to another

Sedimentary – forms when sediments are compacted or cemented together into layers

Sediments – loose rock fragments, mineral grains, and once-living plants & animals that have been eroded

Streak – color of a mineral in its powdered form