Tumbling Blue Amphibole - Mohs 5-6 ?

[andyiii]

Hello again all!

I've got my hands on a bit of rough stone labeled "blue amphibole" from Africa.  Searching google, it is also apparently called "blue quartz", "blue angel phantom quartz", and "blue angelite".

Everything I can find says it is Mohs 5-6.  These rocks "feel" softer, if you know what I mean.

I have only, thus far, tumbled harder rocks in the Mohs 7+ range.  Before I destroy these, should I:

1)  Shorten stage 1 (60/90 SiC), or even skip it entirely?

2)  I plan to roll them in a 3-lb. rotary tumbler until smooth, then shift to vibratory.  Since they are softer, I don't plan to mix in any other rocks, which means I need media to fill the barrel.  Should I limit to plastic media only since it is "softer", or is ceramic just fine?

Any other tips?

Thanks,
Andy III

[titaniumkid]

This might be useful.

[andyiii]

Cool! Thanks - I tried like 10 different search terms and didn't come up with a good result, but didn't try "angelite" since it seemed like a very uncommon name for the stones ...