Rocks and Minerals Crossword

a very hard, granular, crystalline, igneous rock consisting mainly of quartz, mica, and feldspar and often used as a building stone
a speckled, coarse-grained igneous rock consisting essentially of plagioclase, feldspar, and hornblende or other mafic minerals
a hard, dark, glass like volcanic rock formed by the rapid solidification of lava without crystallization
a coarse-grained clastic sedimentary rock that is composed of a substantial fraction of rounded to subangular gravel-size clasts
a clastic sedimentary rock composed mainly of sand-sized mineral particles or rock fragment
a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs
a hard, non-foliated metamorphic rock which was originally pure quartz sandstone
a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
formed through the cooling and solidification of magma or lava
changed to another under the influence of heat, pressure, or some other agent without passing through a liquid phase
often deposited in layers, and frequently contain fossils
a yellow precious metal, the chemical element of atomic number 79, valued especially for use in jewelry and decoration, and to guarantee the value of currencies.
a precious stone consisting of a clear and typically colorless crystalline form of pure carbon, the hardest naturally occurring substance.
a white, gray, or pale green soft mineral with a greasy feel
a combustible black or dark brown rock consisting mainly of carbonized plant matter, found mainly in underground deposits and widely used as fuel