Opal is a silicate and a type of quartz. It is formed when silica fills small spaces in other rocks and is colorless in its pure form. This specimen includes multiple pieces and is stored in a box from J. C. Herkner Jewelry Company of Grand Rapids, Michigan.
J C Herkner Jewelry Company J.C. Herkner Jewelry Company is a long-time business in Grand Rapids. The company, still in business today was founded by Joseph Herkner in 1867 after he served with the 1st Michigan Engineers and Mechanics in the Civil War.