Igneous Rocks

Indigo Gabbro, also known as Mystic Merlinite, is a crystal that belongs to the igneous rock family. It is a unique and visually striking...

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....

The most common intrusive rock in Earth’s continental crust, granite is familiar as a mottled pink, white, gray, and black ornamental stone. It is coarse- to medium-grained. Its three main minerals are feldspar, quartz, and mica, which occur as silvery muscovite or dark biotite or both. Of these minerals

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

Pillow lava is a type of basaltic lava that forms underwater, typically in the ocean. It gets its name from the characteristic pillow-like shapes...

Obsidian is an igneous rock that forms when molten rock material cools so rapidly that atoms are unable to arrange themselves into a crystalline structure. It is an amorphous material known as a "mineraloid." The result is a volcanic glass with a smooth uniform texture that breaks with a conchoidal fracture .

Medium or coarse grained rocks, gabbros Dark green pyroxene in principle (augite and smaller orthopyroxene amounts plus white or green colored plagioclase and black, millimeter sized grains of magnetite and / or ilmenite.

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

Syenite, any of a category of intrusive igneous rocks basically composed of an alkali feldspar and a ferromagnesian mineral. A unique group of alkali syenites is characterized by the presence of a feldspathoid mineral inclusive of nepheline, leucite, cancrinite, or sodalite (see nepheline syenite). Chemically, syenites comprise a slight amount of silica, incredibly big amounts of alkalies, and alumina. The call become first used by Pliny the Elder.

Granodiorite  is a phaneritic-textured intrusive igneous rock similar to granite, but containing more plagioclase feldspar than orthoclase feldspar. According to the QAPF diagram, granodiorite has a greater than 20% quartz by volume, and between 65% to 90% of the feldspar is plagioclase. A greater amount of plagioclase would designate the rock as tonalite.

Phonolite is a type of volcanic rock that belongs to the family of igneous rocks. It is characterized by its unique mineral composition and...

An intrusive igneous rock, peridotite is coarsegrained and dense. It is light to dark green in color. Peridotite contains at least 40 percent olivine and some pyroxene. Unlike the olivine grains, the pyroxene grains in peridotite have a visible cleavage when viewed under a hand lens. Peridotite forms much of Earth’s mantle and can occur as nodules that are brought up from the mantle by kimberlite or basalt magmas.