White cluster of cowlesite crystals on a green clay mineral. At the left and right edge are clusters of a colorless heulandite group mineral.
Zeolites are abundant in boulders scraped off the top of an Eocene basalt flow in order to make the logging road along Big Tree Creek, 3.8 miles east of the railroad tracks in Yacolt, Clark County, Washington. Boulders and dirt was piled along the south side of the road and into the trees making finding the boulders and collecting in them difficult. No rock cut was found containing the same mineralization. The site was found by Jim Babcock of Vancouver, Washington and was made known to other collectors by Vi Frazer. Like most logging roads, the area is closed to collecting and gated.
Collected by me on 7 May 1989
Cowlesite Ca(Al₂Si₃)O₁₀·5-6H₂O
Big Tree Creek, Yacolt, Clark Co., Washington, USA
FOV = 3.27 mm
#1604
NFS
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