Oak

Object/Artifact

-

Crater Rock Museum

Name/Title

Oak

Entry/Object ID

78.58.364

Description

Assemblage Zone: sedimentary Chemical Composition: Si O2 Crystal System: Hexagonal Description: Family: Fagaceae Genus: Quercus Common Name: Oak Age: Mid- Miocene Location data: Ellensburg, Washington Description: Thick slab with polished face. Colors range from creams, browns, greys and some black. Piece is filled with cracks and open areas. Rays are seen. Tropical tree. Delmar described this specimen as a Washington Sycamore, whereas Doug Foster described it as an Oak. Size: 10.00"x 9.500"x 2.00" Type of Fossils Present: Plants Fracture: conchoidal Grain Size: Fine Hardness: 7 Quartz Luster: Glassy Occurrence: Silicified wood, which is the fossilization and/or opalization of organic woody matter by the deposition of SiO2 in a anaerobic environment to prevent decay. This means that the wood must somehow be buried in an oxygen free enviroment, possibly in the silt-laden river or the bottom of a lake or buried by volcanic ash or volcanic related mudflow. The organic material in the wood is then replaced by silica, other minerals determined the colors of the petrified wood. Pressure: Moderate Rock Color: Medium Rock Origin: Post-depositional Rock Type: Sedimentary Specific Gravity: 2.6 Surface Process: Not apparent Streak: white Temperature: Low Texture: microcrystalline Variety: Petrified wood is hydrous microcrystalline variety of quartz that can be defined in general term of chalcedony or opalization

Collection

Petrified Wood Collection

Acquisition

Accession

78.58

Source or Donor

Delmar Smith Petrified Wood Collection

Acquisition Method

Donation

Other Names and Numbers

Other Number

Other Number: 78.58.364

Dimensions

Width

9-1/2 in

Depth

2 in

Length

10 in

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

PW-3

Room

Petrified Wood Room

Building

Crater Rock Museum

Category

Exhibit

Moved By

Jillian Mather Kettley

Date

February 28, 2025

Notes

Installed after rebuild of case 3