Name/Title
MuscoviteEntry/Object ID
2009.62.151Description
Chemical Composition: KAI2(AISi3O10)(F,OH)2
Crystal System: Monoclinic System
Description: Common Name: Muscovite
Chemistry: KAl2(AlSi3O10)(F, OH)2, Potassium aluminum silicate hydroxide fluoride.
Class: Silicates
Location: Maine
Description: Large, thin layered, translucent sheets, smoky brown in color.
PHYSICAL CHARACTERISTICS:
Color is white, silver, yellow, green and brown.
Luster is vitreous to pearly.
Transparency crystals are transparent to translucent.
Crystal System is monoclinic; 2/m
Crystal Habits include tabular crystals with a prominant pinacoid termination. Muscovites four prism faces form diamond shaped "books" and if modified by another pinacoid they form pseudo-hexagonal crystal "books". The sides of the crystal often tend to tapper. Also as lamellar rock forming masses and small flakes in detrital matterial. Twinned crystals can form flat five pointed stars.
Cleavage is perfect in one direction producing thin sheets or flakes.
Fracture is not readily observed due to cleavage but is uneven.
Hardness is 2 - 2.5.
Specific Gravity is approximately 2.8 (average)
Streak is white.
Associated Minerals are quartz, feldspars, beryl and tourmalines.
Other Characteristics: cleavage sheets are flexible and elastic, meaning they can be bent and will flex back to original shape.
Best Field Indicators are crystal habit, cleavage, elastic sheets, color and associations.
Fracture: Uneven
Hardness: 3 Calcite
Luster: Pearly
Occurrence: Notable Occurrences include India, Pakistan, Brazil and many USA locallities.
Rock Type: Metamorphic
Specific Gravity: 2.8
Streak: White
Variety: Muscovite is a common rock forming mineral and is found in igneous, metamorphic and detrital sedimentary rocks.Collection
RAGM Mineral CollectionAcquisition
Accession
2009.62Source or Donor
Museum Collection of MineralsAcquisition Method
DonationDimensions
Width
5 inDepth
1/2 inLength
8 inWeight
1.78 ozLocation
Location
Shelf
CS-E-3Room
Curation StorageBuilding
Crater Rock MuseumCategory
StorageDate
July 29, 2023Location
Container
RightDrawer
Bottom / Back rowShelf
Right, RightWall
West wallRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Steve MillerDate
February 9, 2010Location
Container
RightDrawer
Bottom / Back rowShelf
Right, RightWall
West wallRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Steve MillerDate
February 9, 2010Location
Drawer
2nd from RightShelf
Right bottom back, Right bottom backWall
West wallRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Scott LonganDate
September 26, 2009Location
Cabinet
H-6 rearWall
NorthBuilding
Storage (old gift shop upstairs)Category
Permanent