Rocks

Kakortokite is a rare igneous rock primarily composed of perthitic microcline feldspar with minor amounts of other minerals such as nepheline, sodalite, and/or eudialyte....

Ignimbrite is an expansion of hardened tuff. Ignimbrites are igneous rocks made up by crystal and rock fragments in a glass-shard groundmass, albeit the original texture of the groundmass is probably obliterated due to high degrees of welding. The term ignimbrite isn't always encouraged by means of the IUGS Subcommission on the Systematics of Igneous Rocks.

A granular metamorphic rock, marble is derived from limestone or dolomite. It consists of a mass of interlocking grains of calcite or the mineral dolomite. Marbles form when limestone buried deep in the older layers of Earth’s crust is subjected to heat and pressure from thick layers of overlying sediments.

Monzonite is a type of igneous rock that falls within the category of intrusive or plutonic rocks. It is primarily composed of minerals such...

Volcanic bomb is pyroclastic rock that is a cooling of a mass of lava it flies thorough the air after eruption. If it is...

Oil Shale is organic-rich sedimentary rocks that have contain kerogen (insoluble organic matter in sedimentary rock. When subjected to intense heat, these shales yield...

Scoria is a type of volcanic rock that forms from the solidification of molten lava. It is commonly found around and on the surface...

Boji Stones, also known as Moqui Marbles or Shaman Stones, are small, round, naturally occurring stones found in the Navajo Sandstone formation of Utah...

Amphibolite, a rock composed in large part or dominantly of minerals of the amphibole institution. The term has been implemented to rocks of both igneous or metamorphic foundation. In igneous rocks, the term hornblendite is greater not unusual and restrictive; hornblende is the maximum not unusual amphibole and is traditional of such rocks.

Moon rocks are rocks or regolith (the loose, fragmented material on the surface of the Moon) that have been collected during various Apollo missions...

Arkose is a type of sedimentary rock characterized by its high mineral content of feldspar, particularly orthoclase. It is often considered a type of...

Catlinite, also known as pipestone, is a type of claystone prized by Native American tribes for its unique properties and cultural significance. It is...