Name/Title
Limb Cast with Water LinesEntry/Object ID
06.58.43Description
Assemblage Zone: Volcanic
Chemical Composition: Si O2
Crystal System: Hexagonal
Description: Family: Not Identified
Age: Late Eocene to Early Oligocene
Location data: Wiggens Formation - Wiggens Fork, Wyoming USA
Description: Horizontal banding clear to white agate
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
06.58Source or Donor
Petrified Wood CollectionAcquisition Method
DonationOther Names and Numbers
Other Number
Other Number: 2006.58.43Dimensions
Width
2-1/2 inDepth
1-3/4 inLength
3-1/8 inDimension Notes
Dimension taken at widest pointsLocation
Location
Display Case
PW-13Room
Petrified Wood RoomBuilding
Crater Rock MuseumCategory
ExhibitDate
October 16, 2025Notes
Location added when performing inventory
