Pyrite and Baryte

ID	343
Mineral	Pyrite Baryte
Location	Oumjrane mining area - Alnif - Draa-Tafilalet - Morocco
Fluorescence	LW-UV: close SW-UV: close
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Mindat data

ID	3314
Long ID	1:1:3314:1
Formula	`FeS₂`
IMA Status	0 1
Other Occurrences	Common in many rock types, igneous, metamorphic and sedimentary.
Diapheny	Opaque
Cleavage	Indistinct on {001}.
Tenacity	brittle
Colour	Pale brass-yellow
Hardness (min)	6.0
Hardness (max)	6.5
About the name	Named in antiquity from the Greek "pyr" for "fire", because sparks flew from it when struck with another mineral or metal. Known to Dioscorides (~50 CE) under the name "περι υληζ ιατρικηζ" which included both pyrite and chalcopyrite.
Streak	Greenish-black
Crystal System	Isometric
Cleavage Type	Poor/Indistinct
Fracture type	Irregular/Uneven,Conchoidal
Morphology	Typically cubic or pyritohedral (pentagonal dodecahedral), sometimes octahedral and combinations are common, resulting in striated faces. Less frequently octahedral, most commonly massive, granular, and sometimes radiating, reniform, discoidal or globular.
Twinning	On [110], interpenetrating ('Iron Cross Law'). Twin axis [001] and twin plane {011}, penetration and contact twins. Twinning on (111) was described by Nicol (1904), Goldschmidt and Nicol (1904) and Gaubert (1928), all of whom considered it rare.
UV	Not fluorescent in UV
Thermal Behaviour	Heated in a closed tube gives a sublimate of sulfur and a magnetic residue.
shortcode_ima	Py
Group	Pyrite Group

ID	549
Long ID	1:1:549:0
Formula	`Ba(SO₄)`
IMA Status	0 1
Other Occurrences	Commonly found as a gangue mineral in metallic ore deposits of epithermal or mesothermal origin; but it may also be found as lenses or replacement deposits in sedimentary rocks, both of hypogene and supergene origin.
Industrial	Used as an additive in drilling fluids, as a white pigment, e. g. in cosmetic products and in paints, and as a filling material for polymers and papers, high contrast medium for medical X-rays. Also the main source of barium.
Diapheny	Transparent,Translucent,Opaque
Cleavage	Perfect on {001}; less so on {210}; Imperfect on {010}.
Tenacity	brittle
Colour	Colourless, white, yellow, brown, grey, blue, etc.; colourless in transmitted light (also tinted yellow, brown, green, blue, etc.)
Hardness (min)	3.0
Hardness (max)	3.0
Luminescence	Fluoresces yellows, orange, or pink in LW; phophsphoresces strongly greenish-white.
Lustre	Vitreous to Resinous, Pearly on cleavage surfaces.
About the name	Named in 1800 by Dietrich Ludwig Gustav Karsten from the Greek βαρύς, heavy, due to its unusual heaviness for a non-metallic mineral.
Streak	white
Crystal System	Orthorhombic
Cleavage Type	Perfect
Fracture type	Irregular/Uneven
Morphology	Usually thin to thick tabular {001}, bounded by {210} alone or in combination with {101}, {011} or other forms. Also flattened {001}, and elongated to prismatic [010] or [100]. More rarely prismatic [001], or equant. Often as aggregates or clusters of tabular crystals with edges projecting into crest-like forms, or as rosettes. Also found as massive material, compact, laminated or concretionary; and in fibrous, stalactic, and earthy masses.
UV	Shades of yellow, occasionally orange or pink (LW UV). Shades of yellow, white (Franklin & Sterling Hill, NJ). May phosphoresce strongly greenish-white.
Thermal Behaviour	Inverts to another (monoclinic?) polymorph when heated to 1149°C. Above 1400°C decomposition to barium oxide, sulphur dioxide and oxygen. Thermoluminescent at times.
Comment Luster	Vitreous to Resinous, Pearly on cleavage surfaces.
key_elements	0
shortcode_ima	Brt
Group	Baryte Group

Price: € 550

Dimensions: Not registered

Weight: 4759 g

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Notes:

Symbol	Element
Ba	Barium
Fe	Iron
O	Oxygen
S	Sulfur

Pyrite and Baryte

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