gems, jade, Fischer-Book

Sinkankas: The discussion highlights the desirability of positively identifying stone objects and outlines the methods used for identification, including color, diaphaneity, luster, hardness, and specific gravity, which are sometimes sufficient for accurate identification. It also notes the predominance of color in stones, suggesting that primitive green-colored peoples particularly favored this hue. Additional comments are made on the usefulness of other properties for identification, such as cleavage planes, streak, acid reactions, and optical properties.