https://everything2.com/user/QEDrakmar/writeups/Corundum
Corundum is a trigonal crystal with a chemical base of Al2O3. It has a hardness of 9, and is the hardest of the stones that is measured using the Mohs scale...
corundumthing
https://rocksandbonesllc.com/product/corundum-crystal-north-carolina-32/
Found in Franklin, Canton & Hickory North Carolina Collected 40 years ago Corundum Crystal; 1.65 oz
north carolinacorundumcrystalrocksbones
https://corundummember.wixsite.com/corundum
corundum
https://www.zxabrasives.com/product-details/97.html
White Corundum White corundum is crystallized by electrofusion refining, with high purity, good self-sharpening, acid and alkali corrosion resistance, high...
whitecorundumshandongzhongxingmetal