Embedded Files
Type of rock and how it forms:
Gabbro is a dark igneous rock. Since it crystallizes very deep underground, the high pressure and temperature means crystallization happens very slowly and and thus forms large crystals. For this reason, gabbro is described as “coarse grained”. Basalt is the fine grained version of gabbro.
Minerals in gabbro and variations in appearance:
Gabbro has the same mineral ingredients as basalt (mainly pyroxene and olivine), but basalt is much finer grained because it cools at the Earth’s surface as lava.
Gabbro is usually black or very dark green in appearance. Farmington gabbro has a peppered pink appearance to it, the pink comes from a type of feldspar containing titanium.
Where gabbro is found in NC:
Farmington gabbro is found near Concord, NC and there is basalt mixed in with other igneous and metamorphic rocks scattered around other areas of the western Piedmont.
Uses:
Countertops, tiles and other decorative purposes.
As crushed stone for building and fill purposes.
As a source of valuable minerals such as nickel, gold, silver, platinum and copper.
Fun Facts:
Gabbro is sometimes called “black granite” when used in countertops and tiles.
Dark gravestones are usually made of gabbro.
The Vietnam Veterans Memorial Wall in Washington D.C. is made of gabbro.
Read further at:
Report abuse