Mineralogy

Hello there. This is a blog dedicated to minerals and their properties.

If there's anything you'd like to see, just drop me an ask and I'll see what I can do :)

Apologies for my recent inactivity.

After my exams in a couple weeks from now I will work on making some posts and rebuilding the queue.

ifuckingloveminerals:

Calcurmolite, Umohoite, β-Uranophane, Baryte
Mas d’Alary (Mas d’Alary MCO), Lodève, Hérault, Languedoc-Roussillon, France

Reblogged from ifuckingloveminerals

ifuckingloveminerals:

Calcurmolite, Umohoite, β-Uranophane, Baryte

Mas d’Alary (Mas d’Alary MCO), Lodève, Hérault, Languedoc-Roussillon, France

Kyanite and Metamorphic Facies

Kyanite (which I posted about a couple days ago) has another attribute I did not touch upon: it is used as an index mineral to provide geologists with clues to the environment a rock formed in. In the example of kyanite, its presence indicates that the surrounding rock was exposed to high pressures (over 4 kilobars) but fairly low temperatures, because those are the conditions it forms under and is stable under. Its polymorphs, andalusite and sillimanite, form under lower pressure or higher temperatures, respectively, and are index minerals for those conditions. These environments, indicated by these and other minerals, are known as metamorphic facies.

 Above: a diagram showing the conditions that the polymorphs of Al2SiO5 form under. Source.

By no means are the Al2SiO5 polymorphs the only series of minerals indicating formation conditions. Obviously, the usefulness of kyanite and its polymorphs depends on the chemical composition of the surrounding rocks. For other rock chemistries and other temperature and pressure ranges, there are different series of index minerals. This image on Wikimedia Commons and this Wikipedia page sums up the different facies and the environments they represent.

fuckyeahmineralogy:

Tourmaline; Himalaya Mine, Gem Hill, California

Reblogged from fuckyeahmineralogy

fuckyeahmineralogy:

Tourmaline; Himalaya Mine, Gem Hill, California

Kyanite, a (commonly) blue silicate with the formula Al2SiO5, is a metamorphic mineral with a number of distinguishing properties. Firstly, it is usually blue, although it may also be white or grey, and much more rarely orange, yellow, or pink. Its elongated, bladed crystals and perfect cleavage (*prepares for boob jokes*) also aid in identification. Other crystal habits seen are columnar and tabular habits. An interesting characteristic is its varying hardness (between 5 .5 and 7), depending on its crystallographic direction. Another name for the mineral is disthene, although I’ve never actually heard it by any other name than kyanite, which originates from the Greek word kyanos, meaning “blue”. The French spelling cyanite was also used in the 19th and 20th centuries. Regardless of spelling or name, the mineral finds use in ceramics.
Sources:
Wikipedia | Mindat
Image: Kyanite by Parent Gery. Retrieved from the Commons.

Kyanite, a (commonly) blue silicate with the formula Al2SiO5, is a metamorphic mineral with a number of distinguishing properties. Firstly, it is usually blue, although it may also be white or grey, and much more rarely orange, yellow, or pink. Its elongated, bladed crystals and perfect cleavage (*prepares for boob jokes*) also aid in identification. Other crystal habits seen are columnar and tabular habits. An interesting characteristic is its varying hardness (between 5 .5 and 7), depending on its crystallographic direction. Another name for the mineral is disthene, although I’ve never actually heard it by any other name than kyanite, which originates from the Greek word kyanos, meaning “blue”. The French spelling cyanite was also used in the 19th and 20th centuries. Regardless of spelling or name, the mineral finds use in ceramics.

Sources:

Wikipedia | Mindat

Image: Kyanite by Parent Gery. Retrieved from the Commons.

A specimen of orpiment, more reddish than yellow. Rob Lavinsky/irocks.com via the Commons. From Quiruvilca Mine, Peru.

A specimen of orpiment, more reddish than yellow. Rob Lavinsky/irocks.com via the Commons. From Quiruvilca Mine, Peru.

Sugilite is a rarish purple cyclosilicate mineral with the chemical formula KNa2(Fe,Mn,Al)2Li3Si12O30. It is in fact more commonly light brownish yellow in colour and fairly unattractive. It is named after the Japanese petrologist Ken-ichi Sugi (pronounced with a hard g), although English-speakers frequently mispronounce the name of the mineral, particularly after it became well-known after large quantities of more attractive purple specimens were discovered in South Africa.

It has a Mohs hardness of 6-6.5. It occurs in intrusive syenite rock in its type locality in Japan, in Quebec, Canada, but in its locality at the Wessels Mine in the Northern Cape Province of South Africa it occurs in a metamorphed manganese deposit. Both accompanying images are from the Wessels Mine locality. 

Sources:

Wikipedia | Mindat | Webmineral

Images by Rob Lavinsky via Wikimedia Commons. Links here and here.

ggeology:

Gold

Reblogged from geo5rson

ggeology:

Gold

(Source: ggeology)

Antlerite is a green copper sulphate mineral, with the chemical formula Cu3(SO4)(OH)4. Its colour ranges in shade from light green to emerald green to black, and is translucent with a pale green streak. It has a hardness of 3-3.5. Antlerite occurs in weathered zones of carbonate-poor copper deposits in arid areas. It was originally thought to be fairly rare, but was discovered to be the main ore at the Chuquicamata mine in Chile and Antler mine in Arizona, USA, the latter of which lends the mineral its name. Antlerite is soluble in dilute sulphuric acid; however it can be distinguished from similarly coloured malachite because it does not dissolve in hydrochloric acid (malachite does). It may also be confused with brochantite, with which it is closely related. However, antlerite is less common.
Sources:
Wikipedia | Mindat 
Image: Antlerite from Ingadanais Mines, Castelo Branco, Portugal, by Leon Hupperichs, via Wikimedia Commons. Picture width: 3mm.

Antlerite is a green copper sulphate mineral, with the chemical formula Cu3(SO4)(OH)4. Its colour ranges in shade from light green to emerald green to black, and is translucent with a pale green streak. It has a hardness of 3-3.5. Antlerite occurs in weathered zones of carbonate-poor copper deposits in arid areas. It was originally thought to be fairly rare, but was discovered to be the main ore at the Chuquicamata mine in Chile and Antler mine in Arizona, USA, the latter of which lends the mineral its name. Antlerite is soluble in dilute sulphuric acid; however it can be distinguished from similarly coloured malachite because it does not dissolve in hydrochloric acid (malachite does). It may also be confused with brochantite, with which it is closely related. However, antlerite is less common.

Sources:

Wikipedia | Mindat 

Image: Antlerite from Ingadanais Mines, Castelo Branco, Portugal, by Leon Hupperichs, via Wikimedia Commons. Picture width: 3mm.

Cuprite from Tsumeb, Namibia.
Description from irocks.com:

A stunning specimen of Christamas-colors, with brilliant red cuprite of unusual quality for Tsumeb perched on green-colored calcite matrix. This was , to me, the premier cuprite specimen in the collection and it really leaps out, as it is incredibly sparkly in person and the many facets reflect light every which way.

Cuprite from Tsumeb, Namibia.

Description from irocks.com:

A stunning specimen of Christamas-colors, with brilliant red cuprite of unusual quality for Tsumeb perched on green-colored calcite matrix. This was , to me, the premier cuprite specimen in the collection and it really leaps out, as it is incredibly sparkly in person and the many facets reflect light every which way.