Amygdaloidal Basalt #35

Description

This specimen is an alterred amydaloidal basalt. The amygdules (gas bubbles originally) vary in size, and are filled largely with quartz, epidote, calcite, and chlorite. This basalt has been strongly altered, and now contains much chlorite and hematite. The sample is from the Mohawk Mine in Keweenaw County, Michigan. This sample is 9.5 cm across.