Rocks and Minerals

I'm a masters of geology drop out who still likes getting my rocks off.

[rockon-ro]

Seymchan iron/pallasite meteorite from Magadan District, Russia. Weight is 165 grams. Photo is a cut, polished and acid etched slice of the iron facies of this meteorite fall. The slice displays the classic Widmanstatten pattern (a.k.a. Thomson structure) found in some iron-nickel meteorites. This pattern results from the interweaving of crystals from two iron alloys, kamacite (low nickel) and taenite (high nickel). The Widmanstatten pattern is diagnostic of meteorites as this pattern cannot be duplicated in laboratories on Earth. To form this pattern the iron core of the asteroid must cool no faster than a couple of degrees every million years. In the gaps between the lamellae, a fine-grained mixture of kamacite and taenite called plessite can be seen.

[mypubliclands]

Located on the Colorado Plateau in northern Arizona, Vermilion Cliffs National Monument is a geologic treasure. This remote and unspoiled monument contains 280,000 acres of diverse landscapes – including the colorful swirling stone of the Wave (shown here) – making it an international hiking destination. For those who don’t get a permit to the Wave, White Pocket in Vermilion Cliffs has similar geologic features and is worth the visit!

New photos by Bob Wick, BLM

[dropthemica]

Hey kids thanks for following me even tho I never post. I hope we may find solidarity in a hatred of aura quartz and minerals being ground into crystal shapes. Luv youse.

[ifuckingloveminerals]

Quartz, Realgar

Palomo Mine, Huancavelica, Peru

[dropthemica]

Don't lick realgar it tastes like AsS ahahhahaa

[tenebraris-et-mortis]

[ifuckingloveminerals]

Creedite, Fluorite

[bijoux-et-mineraux]

[ifuckingloveminerals]

Heliodor

Volodarsk-Volynskii, Zhytomyr Oblast’ (Zhitomir Oblast’), Ukraine

[tenebraris-et-mortis]

[ifuckingloveminerals]

Tourmaline

[bijoux-et-mineraux]

Schorl and Smoky Quartz - Davib East Farm 61 (Davib Ost Farm 61), Karibib District, Erongo Region, Namibia

[fatchance]

Exposed rock surfaces in the Pima Canyon Wash, South Mountain Preserve, Phoenix, Arizona. Please click any photo in the set for enlarged views.

“The eastern half of the South Mountains contains granitic rocks that are salt-and-pepper colored on freshly broken surfaces, but are generally coated by a brown or tan veneer of desert varnish. These rocks were formed in the Cenozoic Era only 25 million years ago, when molten rocks solidified in a large chamber several miles below the earth’s surface. The granites are the same age as volcanic rocks of similar composition that dominate the landscape of the Superstition Mountains east of Phoenix. While the granites were cooling and crystallizing, they were sheared by movement on a major, gently inclined fault zone that was discovered during geologic mapping of the range. The shearing took place at high enough temperatures, perhaps 3000 to 4000 C, to produce a foliation, or planar orientation of minerals, in granitic rocks on top of the range. As the granitic rocks continued to cool, the shearing became increasingly brittle and formed a breccia, a rock composed of angular fragments. The fault responsible for this shearing is no longer active and is not likely to cause earthquakes, but is probably present at depth below most of Phoenix, Tempe, and Mesa. Movement on the fault is responsible for the southwest tilt of the Cenozoic volcanic and sedimentary rocks of Camelback Mountain, Tempe Buttes, and Papago Park.”

- Excerpt from “Geologic History of the South Mountains” by Stephen J. Reynolds in Arizona Bureau of Geology and Mineral Technology Fieldnotes, Vol 15, No. 1, Spring 1985.

[earthstory]

One correction I’ve got to add is that 3000 to 4000 degrees is way, way too high. Grantie tends to melt by about 800 degrees C. Every single rock on Earth melts by about 4000 degrees C once its at low enough pressure. 

[rockon-ro]

ROSASITE (Copper Zinc Carbonate) from Mina Ojuela, Mapimi, Durango, Mexico.

[dropthemica]

Why is it left to US NGOs to expose Australian mining's wrongdoing in Africa? Antony Loewenstein, theguardian.com

Australian miners are making a killing overseas. With little regulation or oversight, billions of dollars are being made in some of the most remote places on Earth.

The necessity of partnering with autocratic regimes has proved no impediment to…

While minerals are beautiful and essential, we need to pay more attention to the impacts of mining; particularly when the minerals are sourced from countries other than our own. The scope for exploitation is enormous and the huge amounts of money involved seem to quell peoples' morality sometimes.

[rockon-ro]

AEGIRINE with Quartz / Orthoclase (Sodium-Iron Silicate) from Mount Malosa, Zomba District, Malawi. Black aegirine crystals protrude from a base of white orthoclase feldspar.

[bogglebabbles-main]

Two separate specimens of Cobaltocalcite from Agoudal Mine, Bou Azzer, Morocco. An odd contrast of colour and shape from the same mineral and locality. Like rock-candy and bubblegum.

[earthstory]

Water coming out of the Earth Volcanic explosions are driven mostly by water and carbon dioxide. When magma is at pressure inside the Earth, it can dissolve small amounts of water and carbon dioxide – compounds we’d call “volatile” since they form vapors at the Earth’s surface.  Inside the Earth, these volatiles will dissolve in magma just like carbon dioxide dissolved in a soft drink; release the pressure and the gas will start bubbling out. Eruptions at volcanoes like this one, Kliuchevskoi on the Kamchatka Peninsula, are driven by volatiles. As magma rises towards Earth’s surface, the volatiles separate from the magma, forming gas bubbles that push their way up to the surface and drive explosions. How do these volatiles get inside the Earth? In the case of Kamchatka, it’s actually coming from the Pacific Plate. Kamchatka sits atop a subduction zone, where the Pacific plate sinks into the mantle beneath the Asian continental plate.  The plate sinking into the mantle is covered with sediments including hydrocarbons and clays – compounds that contain carbon dioxide and water. On top of that, the rocks of the oceanic plate itself have been exposed to the waters of the ocean; those rocks will alter, soaking up water and making minerals like serpentine and chlorite that can store water as well. When the oceanic plate sinks into the mantle, it is heated so much that the minerals break down and the volatiles are released. Eventually, some of those volatiles make it back to the surface, pouring out of volcanic cones in clouds like you see from Kliuchevskoi. -JBB Image credit: NASA/ISS https://www.flickr.com/photos/nasamarshall/11894452484/ 

[underthescopeminerals]

Dioptase with Shattuckite

Lustrous green prismatic crystals of dioptase, the main one double terminated and 0.9 cm in length, scattered throughout a crystallized quartz matrix that is coated by blue crystalline shattuckite. 

[bijoux-et-mineraux]

Rhodochrosite and Manganite - Hotazel Mine, Kalahari Mn field, Northern Cape Province, South Africa

[ifuckingloveminerals]

Heinrichite

Krunkelbach Valley Uranium deposit, Menzenschwand, Black Forest, Baden-Württemberg, Germany