#Goodnight! 😴💤💤 Today's pocket rock is Indigo Gabbro from Madagascar. These specimens are commonly sold under the trade name of Mystic Merlinite. This material is very different from other rocks sold under the "Merlinite" trade name, and contains very little Quartz and no Psilomelane. I find their blue color, rather beautiful, and the sparkly golden crystals within the black "spots" makes me think of the night sky. I really like this material a lot! 🌌
According to Geology.com, "Gabbro is a coarse-grained, dark-colored, Intrusive Igneous Rock. It is usually black or dark green in color and composed mainly of the minerals Plagioclase and Augite. It is the most abundant rock in the deep oceanic crust. Gabbro has a variety of uses in the construction industry. It is used for everything from crushed stone base materials at construction sites to polished stone counter tops and floor tiles.
This mineral composition usually gives Gabbro a black to very dark green color. A minor amount of light-colored mineral grains may also be present. Unlike many other Igneous Rocks, Gabbro usually contains very little Quartz.
Gabbros are equivalent in composition to Basalts. The difference between the two rock types is their grain size. Basalts are Extrusive Igneous Rocks that cool quickly and have fine-grained crystals. Gabbros are Intrusive Igneous Rocks that cool slowly and have coarse-grained crystals.
It is often stated that Earth's oceanic crust is made up of Basalt. The word "Basalt" is used because the rocks of the oceanic crust have a "Basaltic" composition. However, only a thin surface Veneer of Oceanic Crust is Basalt. The deeper rocks of the Oceanic Crust are generally coarser-grained Gabbro. Basalt occurs at the surface of the crust because the rocks there have cooled quickly. At greater depth the cooling rate is slower, and large crystals have time to develop." #indigogabbro, #mysticmerlinite, #merlinite, #igneousrock, #gabbro, #basalt, #lavarock, #blue, #indigo, #black, #gold, #nightsky, #lgbt, #gay, #crystals, #stones, #minerals, #gems, #gemstones, #rocks, #geology, #mineralogy, #gemology, #mineralfacts, #nofilter