Rocks

Granite:

Granite is a common type of igneous rock which is granular in texture. Granites can be pink to gray in colo depending on their chemistry and mineralogy. Granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels. Granite is usually found in the continental plates of the Earth's crust. It is nearly always massive, hard and tough, and therefore it has gained widespread use as a construction stone. 

Limestone:

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate. Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera. Limestone makes up about 10% of the total volume of all sedimentary rocks. Limestone has numerous uses: building material, aggregate for the base of roads, white pigment or filler in products such as toothpaste or paints, and chemical feedstock. 

Feldspar:

Feldspars are a group of rock-forming tectosilicate minerals which make up as much as 60% of the Earth's crust. Feldspars crystallize from magma in both intrusive and extrusive igneous rocks, as veins, and are also present in many types of metamorphic rock. Feldspars are also found in many types of sedimentary rock. 

Schists:

Schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Schist contains more than 50% platy and elongated minerals, often finely interleaved with quartz and feldspar. Most schists have been derived from clays and muds which have passed through a series of metamorphic processes involving the production of shales, slates and phyllites.