From Ohio History Central
The word diamond comes from the Greek name for this mineral. For many centuries now, people have admired, pursued and wanted diamonds for their rarity as well as for their beauty. However, diamonds have other very important qualities that make them very useful. Diamond is four times harder than the next hardest natural mineral, corundum, which includes rubies and saphires. Because of this extreme hardness the mineral diamond makes a very good abrasive, and often is used in highly effective cutting tools. Also, diamond has a very high melting point, it conducts heat extremely well, and it is an excellent electrical insulator. Some notes from www.absolutetrivia.com:
- In the 18th century, the French Comte d’Artois owned a set of diamond buttons, each of which had a miniature clock encased inside it.
- Acid will not dissolve a diamond; only intense heat can destroy it.
- Of all the ore dug in diamond mines, only one carat in every 23 tons proves to be a diamond.
Important locations for diamonds are in Africa, India, Brazil, Russia, Australia and Arkansas. Since diamonds occur primarily in igneous rocks, which are not found at the surface in Ohio, they do not occur in this state’s surface bedrock. At least six diamonds have been found in Ohio in sediments deposited by glaciers of the Pleistocene Ice Age. All were small crystals. As with gold, these minerals were carried to Ohio from Canada by glaciers. In recent years, diamond-bearing kimberlite pipes have been discovered in the Canadian shield and they may have been the source for rare Ohio diamonds.