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Buchanan Ranch, Harney County, Oregon, USAi
Regional Level Types
Buchanan RanchMine (Inactive)
Harney CountyCounty
OregonState
USACountry

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PhotosMapsSearch
08906100017361176871070.jpg
Agate, etc.

Buchanan Ranch, Harney County, Oregon, USA
05700340017361135898479.jpg
Agate, etc.

Buchanan Ranch, Harney County, Oregon, USA
08906100017361176871070.jpg
Agate, etc.

Buchanan Ranch, Harney County, Oregon, USA
05700340017361135898479.jpg
Agate, etc.

Buchanan Ranch, Harney County, Oregon, USA
08906100017361176871070.jpg
Agate, etc.

Buchanan Ranch, Harney County, Oregon, USA
05700340017361135898479.jpg
Agate, etc.

Buchanan Ranch, Harney County, Oregon, USA
Latitude & Longitude (WGS84):
43° 38' 21'' North , 118° 37' 40'' West
Latitude & Longitude (decimal):
43.63932,-118.62798
GRN:
N30W62
Type:
Mine (Inactive) - last checked 2024
Köppen climate type:
BSk : Cold semi-arid (steppe) climate
Nearest Settlements:
PlacePopulationDistance
Crane129 (2011)25.2km
Burns2,757 (2017)34.8km
Hines1,525 (2017)37.4km
Seneca193 (2017)61.5km
Mindat Locality ID:
443199
Long-form identifier:
mindat:1:2:443199:5
GUID (UUID V4):
0


Buchanan Ranch is well known, historic Thundereggs locality that was once a pay to dig ranch that has been dug since the 1930s. The ranch was originally mined for Hg (cinnabar deposits) and the thundereggs were considered a nuisance before it became a pay to dig site. Buchanan Thundereggs are highly variable and range in size from a couple inches to a few hundred pounds with eight different beds or pits documented. Thundereggs from the lower levels have light colored soft and crumbly shells, while older thundereggs collected from the upper, original beds have fully silicified hard shells. The cores usually contain hydrothermal agate (sometimes with parallel banding), chalcedony, jasper, quartz xls, and/or common opal, and the colors may include blue, brown, green, white. Bright red cinnabar inclusions can occur in the cores and shells. Buchanan Ranch is currently not open for collecting.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


3 valid minerals.

Rock Types Recorded

Note: data is currently VERY limited. Please bear with us while we work towards adding this information!

Select Rock List Type

Alphabetical List Tree Diagram

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
ⓘCinnabar2.CD.15aHgS
Group 4 - Oxides and Hydroxides
ⓘQuartz
var. Agate		4.DA.05SiO2
ⓘvar. Chalcedony4.DA.05SiO2
ⓘ4.DA.05SiO2
ⓘOpal4.DA.10SiO2 · nH2O

List of minerals for each chemical element

HHydrogen
Hⓘ OpalSiO2 · nH2O
OOxygen
Oⓘ Quartz var. AgateSiO2
Oⓘ Quartz var. ChalcedonySiO2
Oⓘ OpalSiO2 · nH2O
Oⓘ QuartzSiO2
SiSilicon
Siⓘ Quartz var. AgateSiO2
Siⓘ Quartz var. ChalcedonySiO2
Siⓘ OpalSiO2 · nH2O
Siⓘ QuartzSiO2
SSulfur
Sⓘ CinnabarHgS
HgMercury
Hgⓘ CinnabarHgS

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Colburn, R. (2004) The Formation of Thundereggs (Lithophysae). 2004 revision, pp 213-219.
Broughton, P. L. (1975). Robin’s Buchanan Thundereggs, a New Oregon Mining Venture. Rocks & Minerals, 50(2), pp 75-79.
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