356 - Pyrite and Chalk

ID	356
Mineral	Pyrite Chalk
Location	Navajun - Navajun - Spain
Fluorescence	LW-UV: close SW-UV: close
Mindat.org	View Pyrite information at mindat.org View Chalk information at mindat.org

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	49174
Long ID	1:1:49174:9
Entry type	7
Description	A lithified marl, an indurated sedimentary rock consisting chiefly of the same components as marl, ie. an intimate mixture of clay and silt-sized grains and carbonates (usually calcite). Quantitative classifications vary considerably but typically they...

Symbol	Element
Fe	Iron
S	Sulfur

Pyrite and Chalk