Clay And Stone Tests
Raw Clay Tests: from left to right: Sheridan, WY; Ft. Bragg, CA; Crescent City, CA; Comptche, CA; Mendocino, CA
Cone 5 oxidation tests with no additions
from left to right: Comptche, CA; Mendocino, CA; Sheridan, WY,
stone tests:
Wyoming, Oregon, Idaho Stones