Exposing Garnets

Hi all,

I'm looking for advice on how to best expose the garnets(?) in the attached rock.
Ideally, I'd like to remove enough of the matrix to expose buried garnets and display nicely formed crystal faces.

The matrix seems to be pretty soft (< 4), but abrasion with a rotary wire brush is still awfully slow going, and "feels like" it could damage the edges of exposed crystals. I'm not sure how to best remove the matrix without damaging the crystals. I have a few ideas, but thought I'd ask around before wrecking my specimen.

I'm considering:
* Sandblasting with walnut shells
* Vibratory tumbling with walnut shells
* Splitting off layers of the matrix with a chisel or knife

This came from a stream in Windsor county, Vermont, USA.


Thanks for any suggestions!
Jesse

Air abrasion with glass microbeads will work much faster than walnut shell.

Jesse,
This video clip might give you a few ideas for preparing your specimen.

[www.youtube.com]

Thanks for the ideas.
I'm a bit worried that sandblasting with glass beads might damage the crystal edges, but I'll give it a try if I have trouble with other methods.

The youtube video was definitely useful (although the first one that came up was about offroad vehicles -- had to go back one).
I recently picked up an old dental electro-mallet, which might be just the thing to let me delicately chisel away the matrix.


Regards,
Jesse