Name/Title
Kyanite / PyriteEntry/Object ID
2009.62.27Description
Chemical Composition: Al2 SiO5
Crystal System: Triclinic System
Description: Common Name: Kyanite / Pyrite
Chemistry: Al2 SiO5, Aluminum Silicate / FeS2, Iron Sulfide
Group: Silicates / Sulfides
Location: Graves Mountain, Lincoln County, Georgia USA
Description: Small pale blue-sliver crystals with very small crystals of pyrite in a quartzite
PHYSICAL CHARACTERISTICS OF KYANITE:
Color is blue usually but also can be white, gray or green. Color is often not consistent throughout the crystal and can be blotchy or in streaks.
Luster is vitreous to almost pearly.
Transparency crystals are transparent to translucent.
Crystal System is Triclinic; bar 1
Crystal Habits include flat, pinacoid dominated, prismatic crystals often embedded in metamorphic rocks and quartz veins.
Cleavage is good in one direction parallel to the flat pinacoid face.
Fracture is splintery.
Hardness is approximately 4.5 when scratched parallel to the long axis of the crystal and approximately 6.5 when scratched perpendicular to or across the long axis.
Specific Gravity is approximately 3.58+ (above average)
Streak is white.
Associated Minerals are biotite, staurolite, garnets, quartz, andalusite and sillimanite.
Other Characteristics: Sometimes intergrown with staurolite.
Best Field Indicators are crystal habit, color, luster and unusual hardness.
PHYSICAL CHARACTERISTICS OF PYRITE:
Color is brassy yellow.
Luster is metallic.
Transparency: Crystals are opaque.
Crystal System is isometric; bar 3 2/m
Crystal Habits include the cube, octahedron and pyritohedron (a dodecahedron with pentagonal faces) and crystals with combinations of these forms. Good interpenetration twins called iron crosses are rare. Pyrite is commonly found in nodules. A flattened nodular variety called "Pyrite Suns" or "Pyrite Dollars" is popular in rock shops. Also massive or reniform and replaces other minerals and fossils forming pseudomorphs or copies.
Cleavage is very indistinct.
Fracture is conchoidal.
Hardness is 6 - 6.5
Specific Gravity is approximately 5.1+ (heavier than average for metallic minerals)
Streak is greenish black.
Other Characteristics: Brittle, striations on cubic faces caused by crossing of pyritohedron with cube. (note - striations on cube faces also demonstrate pyrite's lower symmetry). Pyrite (unlike gold) is not malleable.
Associated Minerals are quartz, calcite, gold, sphalerite, galena, fluorite and many other minerals. Pyrite is so common it may be quicker to name the unassociated minerals.
Best Field Indicators are crystal habit, hardness, streak, luster and brittleness.
Fracture: splintery
Hardness: 5 Apatite
Luster: Vitreous
Occurrence: Kyanite is commonly found in aluminium-rich metamorphic pegmatites and/or sedimentary rock. Kyanite in metamorphic rocks generally indicates pressures higher than 4 kilobars. Although potentially stable at lower pressure and low temperature, the activity of water is usually high enough under such conditions that it is replaced by hydrous aluminosilicates such as muscovite, pyrophyllite, or kaolinite.
Pyrite is usually found associated with other sulfides or oxides in quartz veins, sedimentary rock, and metamorphic rock, as well as in coal beds, and as a replacement mineral in fossils.
Rock Type: Metamorphic
Specific Gravity: 3.58(above
Streak: White
Texture: crystaline
Variety: Kyanite is a polymorph with two other minerals: andalusite and sillimanite. A polymorph is a mineral that shares the same chemistry but a different crystal structure with another, or other, minerals. Since the three minerals form under different conditions of temperature and pressure, they are diagnostic for those conditions.
Pyrite is the classic "Fool's Gold". There are other shiny brassy yellow minerals, but pyrite is by far the most common and the most often mistaken for gold. It is so common in the earth's crust that it is found in almost every possible environment, hence it has a vast number of forms and varieties.Collection
RAGM Mineral CollectionAcquisition
Accession
2009.62Source or Donor
Museum Collection of MineralsAcquisition Method
DonationDimensions
Width
1-3/4 inDepth
2-3/4 inLength
3-1/4 inWeight
0.67 ozDimension Notes
Dimension taken at widest pointsLocation
Location
Shelf
CS-E-3Room
Curation StorageBuilding
Crater Rock MuseumCategory
StorageMoved By
Jillian Mather KettleyDate
July 29, 2023Location
Container
right* Untyped Location
Needs Updated Location - 2022Category
PermanentMoved By
Scott LonganDate
August 5, 2009Location
Container
CenterDrawer
3rd shelfShelf
Right side, Right sideWall
South wallRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Wendy MondryDate
August 5, 2009Room
Cultural History StorageBuilding
Crater Rock Museum