Final Report - Yola

b. gemstones. hard, beautiful, and durable substances. iii. 4-3 what is a rock? rock = hard substance composed of 2 or more minerals. relative aging = determining how old rocks are . compared to other rocks. a. types of rocks. rocks are classified according to how they . form. igneous rocks. igneous = formed from magma. igneous rock types: ................
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