Moores sanding discs - sand or garnet. What's the difference?

Hi, I’ve heard about Moores sanding discs that come in different grades and sizes. There’s also sand and garnet. Does anyone know what the difference is between sand and garnet? None of the online stores that sell them, that I have found found so far, give an explanation about the difference. From what I can see online, they are used in medical and podiatry applications.

Also, I’ve seen questions posted about about the discs no longer being available in the same style. Perhaps the ones I’ve seen here in New Zealand are older stock. I’ll have to make enquiries.

Thanks,
Rodney

Sand is silicon dioxide, quartz basically, it breaks down rather too quickly for use on metal, IMHO. Garnet also doesn’t wear well on metal, though it’s OK for woodworking. Stick with aluminum oxide grit. Aluminum oxide is corundum, 9 on the Mohs scale, and is better for metal than the others. Emery is mostly aluminum oxide and has been the standard abrasive for metal for centuries. Silicon carbide is a bit harder, but the fracture patterns of the two are different. It’s better for steel, but not superior for precious metals in my experience.
Here’s a link to Moore’s website. You can browse their products, and there’s a use chart available though mostly it describes the discs’ use for dentistry.
http://www.ecmoore.com/

Thanks for that information, Elliot. I’ve checked out the Moore’s website. I’ll have to do a bit more research. Anyway, emery paper works well for most things.
Cheers,
Rodney