Boulder

We can tell you that Boulder is a…

• …Rock type

If you know more about Boulder, you can add more facts here »

Similar topics in Freebase

• 

  Coal

  Coal is a readily combustible black or brownish-black sedimentary rock normally occurring in rock strata in layers or veins called coal beds. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. It is composed...
• 

  Gypsum

  Gypsum is a very soft mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4 · 2 H2O. Gypsum occurs in nature as flattened and often twinned crystals and transparent cleavable masses called selenite. It may also occur in a silky, fibrous form, in which case it is commonly...
• 

  Granite

  Granite (pronounced /ˈɡrænɪt/) is a common and widely occurring type of intrusive, felsic, igneous rock. Granites usually have a medium to coarse grained texture. Occasionally some individual crystals (phenocrysts) are larger than the groundmass in which case the texture is known as porphyritic. A...
• 

  Igneous rock

  Igneous rock (from the Latin ignis meaning born of fire) is one of the three main rock types (the others being sedimentary and metamorphic rock). Igneous rock is formed by magma (molten rock) cooling and becoming solid. Igneous rock may form with or without crystallization, either below the surface...
• 

  Limestone

  Limestone is a sedimentary rock composed largely of the mineral calcite (calcium carbonate: CaCO3). The deposition of limestone strata is often a by-product and indicator of biological activity in the geologic record. Calcium (along with nitrogen, phosphorus, and potassium) is a key mineral to...
• 

  Marble

  Marble is a non foliated metamorphic rock resulting from the metamorphism of limestone, composed mostly of calcite (a crystalline form of calcium carbonate, CaCO3). It is extensively used for sculpture, as a building material, and in many other applications. The word "marble" derives from the...
• 

  Lignite

  Lignite, often referred to as brown coal, or Rosebud coal by Northern Pacific Railroad, is a soft brown fuel with characteristics that put it somewhere between coal and peat. It is considered the lowest rank of coal; it is mined in Russia, the United States, Australia and many European countries,...
• 

  Basalt

  Basalt (pronounced /bəˈsɔːlt, ˈbeisɔːlt, ˈbæsɔːlt/) is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria....
• 

  Flint

  Flint (or flintstone) is a hard, sedimentary cryptocrystalline form of the mineral quartz, categorized as a variety of chert. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones. Inside the nodule, flint is usually dark grey, black, green, white, or brown in...
• 

  Slate

  Slate is 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. The result is a foliated rock in which the foliation may not correspond to the original sedimentary layering...