Kimberlite
Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
Mineral NameKimberlite
Chemical FormulaComplex silicate rock, primarily composed of olivine, phlogopite, pyroxene, and garnet, often serpentinized and carbonated.
Mohs HardnessVariable (composed of multiple minerals), matrix typically 4-6
Streak ColorGrayish to brownish
CleavageNot applicable (igneous rock)
FractureUneven to conchoidal
Specific Gravity2.8
Colorsdark gray, greenish-black, reddish-brown, yellowish-green
TransparencyOpaque
Type LocalityChicken Park Kimberlite Pipe, State Line Kimberlite Field, Larimer County, northern Colorado, USA
Mineral GroupIgneous rock (ultramafic, potassic)
Useshost rock for diamonds (gem and industrial grade), scientific study
Associated Mineralsolivine, phlogopite, pyroxene, garnet, chromite, ilmenite, serpentine, calcite, diamond
Description
A dark gray to greenish-black rock with a fine-grained matrix, containing visible phenocrysts of reddish-brown garnets and yellowish-green altered olivine.
Geological Context
Kimberlites are unusual igneous bodies that form pipe-shaped intrusions, originating from deep within the Earth's mantle and rapidly ascending to the surface. They are known for their association with diamonds.
