Name/Title
AdulariaEntry/Object ID
2009.62.138Description
Crystal System: Monoclinic System
Description: Common Name: Adularia
Chemistry: KAlSi3O8, Potasium Aluminum Silicate.
Group: Feldspars
Location: Mexico
Description: Layered, multi-directional translucent crystals cream to light yellow in color with a thick layer of druzy-like transparent quartz crystals covering most of the specimen.
PHYSICAL CHARACTERISTICS:
Color is off-white, yellow, or shades of red, orange to brown.
Luster is vitreous to dull if weathered.
Transparency crystals are usually opaque, may be translucent or rarely transparent.
Crystal System is monoclinic; 2/m
Crystal Habits include blocky or tabular crystals. Crystals have a nearly rectangular or square cross-section with slightly slanted dome and pinacoid terminations. Twinning is common. (see above). A psuedo-orthorhombic or psuedo-trigonal variety, found in alpine veins is called adularia, and forms more flattened tabular crystals.
Cleavage is good in 2 directions forming nearly right angled prisms.
Fracture is conchoidal or uneven
Hardness is 6
Specific Gravity is approximately 2.53 - 2.56 (average)
Streak is white.
Associated Minerals are quartz, plagioclase feldspars, micas, garnets, tourmalines and topaz.
Other Characteristics: some crystals may show opalescence and are called moonstone.
Best Field Indicators color, lack of striations, cleavage, twinning if present and occurrence.
Fracture: Irregular
Hardness: 6 Orthoclase
Luster: Glassy
Rock Type: Igneous
Specific Gravity: 2.61
Streak: whiteCollection
RAGM Mineral CollectionAcquisition
Accession
2009.62Source or Donor
Museum Collection of MineralsAcquisition Method
DonationDimensions
Width
7 inDepth
1-5/8 inLength
5-1/8 inWeight
2.22 ozLocation
Location
Container
CenterDrawer
3rd ShelfShelf
Right, RightWall
West wallRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Steve MillerDate
January 30, 2010Location
Drawer
4th from rightShelf
Right side Middle sh, Right side Middle shWall
West wallRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Scott LonganDate
September 26, 2009Location
Container
CenterDrawer
3rd ShelfShelf
RightCabinet
case #58Wall
West wallRoom
Delmar Smith HallBuilding
Crater Rock MuseumCategory
Permanent