Dims: 0.7 x 0.5 x 0.5" (1.7 x 1.3 x 1.2 cm)
Wt: 2 g
Rock Island Dam, Wenatchee, Washington, U.S.A.
A thin matte of pale-brown, almost wool-like Erionite lines some of the hollows inside the oolitic basalt or rhyolite tuff matrix of this small thumbnail piece. These "crystals" are so small as to be difficult to study even with a loupe- I cannot define much more than their color and their fine, needle-like habit. Its brown coloration is unusual, and is likely caused by iron staining. Other hollows contain crusts of darker offretite crystals that are very similar to Erionite in most aspects. The piece is protected inside a small plastic box.