Name/Title
Limb CastEntry/Object ID
08.58.1Description
Chemical Composition: Si O2
Crystal System: Hexagonal
Description: Age: Unknown
Location data: Crooked River, Crook County Oregon USA
Description: Polished face that is clear, white, beige agate with green running through on one side, and crystalline pocket in the center. Outer pinkish agate with blue/greyish woody appearance.
Size: Diameter: 5 1/4" Length: 5 1/2"
Type of Fossils Present: Plants
Fracture: conchoidal
Grain Size: Fine
Hardness: 7 Quartz
Luster: Glassy
Occurrence: Like petrified wood, limb cast are created in much the same manner. Volcanic ash or silica-rich sediment buries a tree limb, the limb decays, leaving behind an open void. This void works as a mold that fills with amorphous silica that has percolated through the surrounding rock. Once microamorphous silica has filled the mold and the crystallization process to a (quartz)chalcedony or opal is complete, the result is a siliceous rock with the same exterior markings as the original limb.
Pressure: Low-Moderate
Rock Color: Light
Rock Origin: Post-depositional
Rock Type: Sedimentary
Specific Gravity: 2.6
Surface Process: Not apparent
Temperature: Low
Texture: Microcrystalline
Variety: Petrified woods ar hydrous microcrystalline varieties of quartz that can be generally termed as chalcedony or opalized .Collection
Petrified Wood CollectionAcquisition
Accession
08.58Source or Donor
Petrified Wood CollectionAcquisition Method
DonationOther Names and Numbers
Other Number
Other Number: 2008.58.1Dimensions
Length
5-1/2 inDiameter
5-1/4 inDimension Notes
Dimension taken at widest pointsLocation
Location
Container
CenterDrawer
BottomShelf
RightCabinet
Case #100Wall
South wallBuilding
Mentzer Hall - Petrified Wood RoomCategory
Permanent
