Search Results for: Toothed wheels
traditional sources of alluvial rubies and sapphires include burma, cambodia, sri lanka, india, afghanistan, montana, and other areas. in the past few decades, several parts of africa, including madagascar, kenya, tanzania, nigeria, and malawi, have become important producers of ruby and sapphire. emery wheels
: an ad offering emery and corundum wheels, published in by the springfield manufacturing company of bridgeport, connecticut. this was at a time when genuine emery and corundum were used to make the wheels. hardness and use as an abrasive the extreme hardness of corundum makes it especially useful as...
https://geology.com/minerals/corundum.shtml