1. name the igneous rock in which crystals of biotite mica are larger than 10 mm in diameter.

2. Identify the luster, hardness, and dominant form of breakage for members of the mica family.

3. Large crystals of mica, sometimes weighing several hundred tons, have been found in igneous
rock in Canada. Identify the environment of formation and the relative rate of cooling of the magma
that formed the igneous rock containing these large crystals.