GEMHUBNatural Blue Sapphire & Ruby Gemstones 100 Ct. Set of 7 Pcs Faceted Sapphire, Ruby Loose Gems For Jewelry Making

Watch the video. Those kind corundums are not created in any lab but at home possibly using fusing aluminium oxide and chromium only maybe because colour is not red but artificially pinkish blue are usually cobalt filled glass but those are worst the I ever seen. So price wise they are worth pennies not over 10 pounds nor near. You can fuse aluminium oxide with chromium and produce same in microwave at home watch some videos online and those are cracked all over inside as it did not fuse well due to not being produced in any lab so called but at home in poor conditions. True review. Stone are synthetic with a specific gravity just above corundums. Corundum specific gravity should be 3.95 to 4.05. Those are more like 4.10 to 4.15 which proves it is corundum but not real. As it's out of range and quality is lowest you can ever find. Honest review from a gemstone cutter I will explain In Video