1 Sapphire blue is a cool color. 2  Sapphire carries the blue symbolism of importance and confidence. 3  Although it's not a light or pastel blue, it still has something of a fresh, spring-like quality with a touch of childlike playfulness.
Sedimentary rocks make up only 5% (by volume) of the upper 10 miles of the crust, but about 75% of the outcrops on the continents. Two primary types of sedimentary rocks: 1  Chemical-precipitate from solution (e.g., limestone); most important constituents are calcite, dolomite, chalcedony (SiO2), gypsum, and halite.2  Chemical sedimentary rocks can be further divided as to: 3  inorganic (e.g., limestone, rock salt, dolomite). Chemical-precipitate from solution (e.g., limestone); most important constituents are calcite, dolomite, chalcedony (SiO2), gypsum, and halite. 2  Chemical sedimentary rocks can be further divided as to: 3  inorganic (e.g., limestone, rock salt, dolomite). 4  organic (e.g., limestone or coal).
Common clastic sedimentary rocks in Pennsylvania are conglomerate, sandstone, siltstone, claystone, and shale. Common nonclastic sedimentary rocks are limestone and dolomite. Igneous rocks are formed by the cooling of molten material, either lava (above ground) or magma (underground).