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Clinoclase

Cu3AsO4(OH)3

Locality:

Majuba Hill Mine (Majuba Mine; Mylar Mine; Tin Mine; Nevada Bureau of Mines and Geology sample sites 2844 & 2846), Antelope District, Pershing Co., Nevada, USA

Field of View: 2.5 mm

Blue green aggregates of Clinoclase. The bright green grains are probably Cornwallite. 

Collection and photo Stephan Wolfsried

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Euchlorine

KNaCu3O(SO4)3

Locality:

Second scoria cone, Northern Breakthrough (North Breach), Great Fissure eruption (Main Fracture), Tolbachik volcano, Kamchatka Oblast’, Far-Eastern Region, Russia

Field of View: 2 mm

Collection and Photo Stephan Wolfsried

Euchlorine -  rare sublimate around volcanic fumaroles. Partially soluble in water.

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Hematite, Durangite

Locality:

Durangite locality, Thomas Range, Juab Co., Utah, USA

A metallic grey, hexagonal crystal of Hematite with a red-orange crystal of Durangite attached to it.

Alex Earl’s Photo

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Hemimorphite, Pyrolusite

Locality:

Rivet Quarry, Montredon-Labessonnié, Réalmont, Tarn, Midi-Pyrénées, France

François Le Gaillard’s Photo 

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Olivenite

Cu2(AsO4)(OH)

Locality:

Clara Mine, Rankach valley, Oberwolfach, Wolfach, Black Forest, Baden-Württemberg, Germany

Field of View: 2.8 mm

Jean-Paul Fayard’s Photo 

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Simonkolleite

Zn5(OH)8Cl2·H2O

Locality:

Genna zinc smelter slag locality, Letmathe, Iserlohn, Sauerland, North Rhine-Westphalia, Germany

Field of View: 2.5 mm

Collection and photo Stephan Wolfsried

Simonkolleite  occurs as a product of weathering of zinc-bearing slags and is associated with native zinc, hydrocerussite, diaboleite, zincite and hydrozincite.

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Erythrite

Co3(AsO4)2·8H2O

Locality:

Bou Azer District (Bou Azzer District), Tazenakht, Ouarzazate Province, Drâa-Tafilalet Region, Morocco

Field of View: 3 mm

Collection and photo Stephan Wolfsried

Erythrite is a deeply colored reddish or pink mineral, with its distinctive color caused by its cobalt content. Erythrite is the end member of a series with Annabergite, with Erythrite being the cobalt-dominant member and Annabergite being the nickel-dominant member. Erythrite is named from the Greek erythros, red, in reference to the hue of this mineral. 

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Siderite, Quartz

Heart shaped Siderite for all of my followers ❤ FeCO3, SiO2

Locality:

San Carlos Mine, Hiendelaencina, Guadalajara, Castile-La Mancha, Spain

Field of View: 2 mm

Juan Miguel Segura’s Photo

Siderite is typically found as brown to tan rhombohedrons in clusters, faces often curved or composites; more often found as medium to dark brown massive fine grained material or as massive crystalline material with exposed curved cleavage surfaces.  Slighty soluble in water. Fungi like Lichenothelia may oxidize iron to produce siderite, which is then a biomineral (e.g., Burford et al., 2003).

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Lepidolite

K(Li,Al)3(Si,Al)4O10(F,OH)2

Locality:

Varuträsk, Skellefteå, Västerbotten, Sweden

Almost translucent 6 mm crystal of Lepidolite in pegmatite matrix.

Volker Betz’s Photo

Lepidolite is a violet to pink variety of Mica. Massive fine-grained material is used for ornamental purposes, it is polished into various shapes - cabochons and slabs. Transparent to translucent material is sometimes faceted. It is a common matrix mineral to Tourmaline and Quartz, providing them with a very aesthetic and glittery base. 

Hardness: 2.5 - 3

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Realgar

AsS

Locality:

Cavnic Mine (Kapnikbánya), Cavnic (Kapnic; Kapnik), Maramureș Co., Romania

Field of View: 3 mm

Photo & Collection: Christophe Boutry

Realgar is an historically important mineral, with a striking ruby-red color that stands out in the mineral kingdom. The rare transparent lustrous forms are truly masterpieces in mineral aesthetics. Realgar is a photosensitive mineral and will alter to Pararealgar upon prolonged exposure to light. Pararealgar is unstable and will eventually crumble into a yellow powder if left in the light. 

Realgar contains a significant amount of poisonous arsenic, and is itself somewhat toxic. Washing hands is recommended after handling Realgar specimens, especially if they are powdery. 

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Anatase Adra, Almería, Andalusia, Spain

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Mexican Fire Agate

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Hematite var. Kidney Ore Cleator Moor, West Cumberland Iron Field, Cumbria, England

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This #MineralMonday, let’s learn about synthetic gems. A synthetic gemstone is created in a lab but is the same substance as the natural gemstone.💎

In 1902, French chemist Auguste Verneuil announced his method for producing synthetic ruby–the first commercial synthetic gem ever created. The Verneuil process, or flame fusion, melts powdered gem material in a flame onto a rod. Other processes include pulling crystals from molten gem material, or growing them from molten mixtures with a flux from high-temperature hydrous fluid.

Photo: E. Louis/© AMNH

#NewYorkRocks #gems #minerals #SyntheticGems #amnh #NaturalHistory #jewelry #geology #jewels (at American Museum of Natural History) https://www.instagram.com/p/CcxpLqiLx9o/?igshid=NGJjMDIxMWI=

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A stunning (and massive) opalized ammonite shell at the Perot Museum of Nature and Science in Dallas, TX. Opalized fossils may form if the remains of an organism are preserved in silica as opposed to limestone.

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Have you ever wondered how big crystals form? Let’s talk about it this #MineralMonday.💎

Pegmatites produce large crystals—usually over ~1⁄2 inch (1 cm)—and are the final product of some cooling magmas. They’re found in veins, dikes, or pods at or near the margins of large igneous bodies. Large crystals and distinctive textures can form in pegmatites because high concentrations of water and certain chemical elements in their magmas reduce the number of crystal nuclei that form. Water also allows pockets to form where minerals, like this beryl (variety: aquamarine), can grow unimpeded as large well-defined crystals.

Photo: E. Louis/© AMNH

#NewYorkRocks #crystals #gems #minerals #NaturalHistory #amnh (at American Museum of Natural History) https://www.instagram.com/p/CbXXBdoLnYh/?utm_medium=tumblr

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Quartz with Hematite inclusions Itremo massif, Itremo Commune, Ambatofinandrahana District, Fianarantsoa Province, Madagascar