Kyanite, Quartz and Dravite

ID	664
Mineral	Kyanite Quartz Dravite
Location	Barra do Salinas - Minas Gerais - Brazil
Fluorescence	LW-UV: close SW-UV: close
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Mindat data

ID	2303
Long ID	1:1:2303:6
Formula	`Al₂OSiO₄`
IMA Status	APPROVED GRANDFATHERED
Description	Common metamorphic silicate mineral. The generally bluish colour is caused by Fe(II)-Fe(III) charge transfer (Faye and Nickel, 1969).
Occurrence	In medium to high pressure and low to medium temperature metamorphic rocks.
Other Occurrences	Metamorphic rocks of moderately high-pressure regional metamorphism.
Industrial	Ceramics
Diapheny	Transparent,Translucent
Cleavage	Perfect on (100), good on (010)
Tenacity	brittle
Colour	Blue, white, light gray, green, rarely yellow, orange, pink
Hardness (min)	5.5
Hardness (max)	7.0
Lustre	Vitreous
About the name	Named in 1789 by Abraham Gottlob Werner from the Greek word "kyanos", meaning "blue," the common colour of the species. The French spelling, "Cyanite", was commonly used by mineralogists through much of the 19th and early 20th centuries.
Streak	Colorless
Crystal System	Triclinic
Cleavage Type	Perfect
Fracture type	Splintery
Morphology	Crystals bladed or tabular.
Twinning	Lamellar on (100), common
UV	Not usually fluorescent. Weak pink-red fluorescence under longwave reported at Thomaston Dam, Connecticut (Don Swenson, pers. com., 2017). Robbins (1994) indicated that: "From Pfitsch in the Tyrol, Austria, colorless blades of kyanite fluoresce yellow under short-wave and orange under long-wave ultraviolet. From research done some years ago on certain kyanite from this locality, and also on kyanite from the Transvaal in South Africa, red fluorescence is reported. The fluorescence is due to trivalent chromium in place of aluminum."
Comment Luster	Somewhat pearly on {100} \|\| to the perfect cleavage
shortcode_ima	Ky

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

Price: € 775

Dimensions: None mm x None mm x None mm

Weight: Not registered

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Notes:

Symbol	Element
Al	Aluminium
O	Oxygen
Si	Silicium

Kyanite, Quartz and Dravite

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