Any corundum without trace elements is colorless. Corundum with trace chemical impurities makes the gems we know. Chromium gives the red to rubies, sapphire has iron and titanium, you can get other colors using vanadium or different ratios. Gems are neat.
Would that make it a type of sapphire?
Types of corundum maybe but I think that’s a stretch. Sapphire is (usually) blue Al2O3. Ruby is red Al2O3. Transparent aluminum is Al2O27N5.
Watch faces are often colorless sapphire; I think industrially produced.
Any corundum without trace elements is colorless. Corundum with trace chemical impurities makes the gems we know. Chromium gives the red to rubies, sapphire has iron and titanium, you can get other colors using vanadium or different ratios. Gems are neat.
Ah so my watch branded the face as “sapphire” because it sounded more sellable than “corundum”?
My thoughts too, what makes this alloy so amazing? It seems to me that sapphire is harder, and otherwise similar use cases
No mention/comparison to Sapphire in the article that I could see, disappointing.
Maybe it is the sintering process that makes it interesting, could be easier to shape maybe 🤔
Aluminum oxynitride is transparent aluminum, but alpha aluminum oxide, which is also transparent, is called Corundum.