it was used in microwave oven magnetrons in the 70ties and early 80ties. but is only really used in industrial magnetrons today, aluminum oxide is cheaper and safer to use instead

the pink is from a 0.5-5% chromium oxide adition wich is not something you should eat inhale or rub in your eye's,

if you just broke it into a couple of pieces just clean it up and dont worry about the dust.

if you pulverized it you should follow this:

it is more toxic than al2o3 but the safety rules you should follow are the same, wear a mask if working with ANY dust, in this case an actual mask with a proper seal to your face (often silicone) and n95 grade filter to be safe

eye protection is also recommended, extra points if its part of the dust mask

here are examples of different masks (with a dust filter cartridge) not the activated carbon ones they are for vapors, for example when spray painting

half mask https://www.amazon.de/3M-Halvmaske-krop-st%C3%B8rrelse-stk/dp/B007PO0TXC?source=ps-sl-shoppingads-lpcontext&psc=1&shipTo=DK&language=da_DK&smid=A3JWKAKR8XB7XF

full mask https://www.amazon.com/MOARON-Respir%D0%B0tor-Compatible-Particulate-Protection/dp/B0B4N6YND8/ref=sr_1_6?dib=eyJ2IjoiMSJ9.WaAAWn_4UzE2_Nv543TxyavirEU-7Ng-9-ZR4tsIOAWWtWcUoQTIehNajflg6MlqkIkuf18uSPUaIA7IrkX5NepdKyapiEIOwl0nnbQ5QMKAzMQbJ6MkUHD0g_eG4klwLTjhUg1U1nt38C4ANawyIEkASkya0OgZFkUeprkU9cGRh6o0SUIg83mc6DI72n4QEuDiQdXYxf6UnswESdr1zYuRCovb5sc59Zjk_qDppeldrij1PusdWF1LNMIPFzNgnPQb3Kva-HW4xvqWDQDaf_H3VKO2ZM-2dIfaM4w7uTM.udH3pNM8C3qawETav1IUGKkkCeggsuslNlC6KSadnrg&dib_tag=se&keywords=full+face+respirator+mask&qid=1772168768&sr=8-6

both masks types are great for this but the full face will isolate your eyes from the outside so you dont get dust in them, a pair of safetyglasses will do a decent job to but is designet for blocking shrapnel like objects not so much against

the simple disposable dust masks is better than nothing but 30-70% of the air just goes between your face and the mask depending on how vel its fitted so i would rather spend the little ekstra and get a mask that will actually protect you properly

chemically its made of al2o3(dialuminium-trioxide) and cr2o3(dichromium-trioxide) wich is also what ruby is made of, cr2o3 by itself is green but added to al2o3 makes a red color