Pyrite, Quartz and Sphalerite

ID	641
Mineral	Pyrite Quartz Sphalerite
Location	Pasto Bueno - Pampas - Peru
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	APPROVED GRANDFATHERED
Description	Pyrite Group. The isometric (cubic) polymorph of orthorhombic marcasite. However, some pyrites may be trigonal (pseudo-cubic; Moëlo, 2023). Compare UM1997-43-S:Fe. Pyrite is a very common mineral and is one of the most common natural sulfides ...
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) and mentioned in book 5 of his 5-volume work "περι υληζ ιατρικηζ" (transliteration: "Peri hulēs iatrikēs"), both meaning "On Medical Material". "Purites lithos" (an umbrella term for both pyrite and chalcopyrite) was used (together with honey) to treat skin problems.
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

ID	3337
Long ID	1:1:3337:0
Formula	`SiO₂`
IMA Status	APPROVED GRANDFATHERED
Description	Quartz is one of the most common minerals found in the Earth's crust. If pure, quartz forms colourless, transparent and very hard crystals with a glass-like lustre. A significant component of many igneous, metamorphic and sedimentary rocks, this natura...
Other Occurrences	Most of them...
Industrial	Ore for silicon, glassmaking, frequency standards, optical instruments, silica source for concrete setting, filtering agents as sand, fracing sand used in oil production. A major component of sand. High purity quartz is used as an ore for creating sili
Diapheny	Transparent,Translucent
Cleavage	The rhombohedral cleavage r{10_11} is most often seen, there are at least six others reported.
Tenacity	brittle
Colour	Colorless, purple, rose, red, black, yellow, brown, green, blue, orange, etc.
Hardness (min)	7.0
Hardness (max)	7.0
Luminescence	Triboluminescent
Lustre	Vitreous
About the name	Quartz has been known and appreciated since pre-historic times. The most ancient name known is recorded by Theophrastus in about 300-325 BCE, κρύσταλλος or kristallos. The varietal names, rock crystal and Bergkristall (German), preserve the ancient usage. The root words κρύοσ signifying ice-cold and στέλλειυ to contract (or solidify) suggest the ancient belief that kristallos was permanently solidified ice. The earliest printed use of "querz" was anonymously published in 1505, but attributed to a physician in Freiberg, Germany, Ulrich Rülein von Kalbe (a.k.a. Rülein von Calw, 1527). Agricola used the spelling "quarzum" (Agricola, 1530) as well as "querze", but Agricola also referred to "crystallum", "silicum", "silex", and silice". Tomkeieff (1941) suggested an etymology for quartz: "The Saxon miners called large veins - Gänge, and the small cross veins or stringers - Querklüfte. The name ore (Erz, Ertz) was applied to the metallic minerals, the gangue or to the vein material as a whole. In the Erzgebirge, silver ore is frequently found in small cross veins composed of silica. It may be that this ore was called by the Saxon miners 'Querkluftertz' or the cross-vein-ore. Such a clumsy word as 'Querkluftertz' could easily be condensed to 'Querertz' and then to 'Quertz', and eventually become 'Quarz' in German, 'quarzum' in Latin and 'quartz' in English." Tomkeieff (1941, q.v.) noted that "quarz", in its various spellings, was not used by other noted contemporary authors. "Quarz" was used in later literature referring to the Saxony mining district, but seldom elsewhere. Gradually, there were more references to quartz: E. Brown in 1685 and Johan Gottschalk Wallerius in 1747. In 1669, Nicolaus Steno (Niels Steensen) obliquely formulated the concept of the constancy of interfacial angles in the caption of an illustration of quartz crystals. He referred to them as "cristallus" and "crystallus montium". Tomkeieff (1941) also noted that Erasmus Bartholinus (1669) used the various spellings for "crystal" to signify other species than quartz and that crystal could refer to other "angulata corpora" (bodies with angles): "In any case in the second half of the XVIIIth century quartz became established as a name of a particular mineral and the name crystal became a generic term synonymous with the old term 'corpus angulatum'."
Streak	White
Crystal System	Trigonal
Cleavage Type	Poor/Indistinct
Fracture type	Conchoidal
Twinning	Dauphiné law. [[1]] Brazil law. Japan law. Others for beta-quartz...
Thermal Behaviour	Transforms to beta-quartz at 573° C and 1 bar (100 kPa) pressure.
shortcode_ima	Qz

ID	3727
Long ID	1:1:3727:9
Formula	`ZnS`
IMA Status	APPROVED GRANDFATHERED
Description	Sphalerite Group. Sphalerite, also known as blende or zinc blende, is the major ore of zinc. When pure (with little or no iron) it forms clear to white crystals (known as cleiophane). Yellow to orange sphalerite is often called 'golden sphalerite'. ...
Discovery Year	1847
Diapheny	Transparent,Translucent
Cleavage	Perfect {011}
Tenacity	brittle
Colour	Mostly light to dark brown to black,. Less commonly red, red-brown, colourless, light blue, or green
Hardness (min)	3.5
Hardness (max)	4.0
Luminescence	Fluorescent and triboluminescent
Lustre	Resinous
About the name	Originally called blende in 1546 by Georgius Agricola (Georg Bauer). Known by a variety of chemical-based names subsequent to Agricola and before Glocker, including "zincum". Named Sphalerite in 1847 by Ernst Friedrich Glocker from the Greek σφαλεροζ "sphaleros" = treacherous, in allusion to the ease with which dark varieties were mistaken for galena, but yielded no lead.
Streak	Pale yellow to brown.
Crystal System	Isometric
Cleavage Type	Perfect
Fracture type	Conchoidal
Twinning	{111}
UV	Light colored sphalerite may fluoresce in blue or orange in LW. Fluoresces less strongly, sometimes not at all, in SW or MW.
key_elements	Zn
shortcode_ima	Sp

Price: € 27

Dimensions: None mm x None mm x None mm

Weight: Not registered

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Symbol	Element
Fe	Iron
O	Oxygen
S	Sulfur
Si	Silicium
Zn	Zinc

Pyrite, Quartz and Sphalerite

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