Prehnite

Does anyone have any tips on how to clean up prehnite to see if it is worth processing further? I dont want to just hit it with a hammer as it has a good chance of being clear and jewellery quality.
The photos are to big to attach however the prehnite has a hard shell of some sort of proper hard rock.

Grind it off.... Be careful with Chemicals....

LW....

Hi Shep.

All I can think of is basically the same as LW has said. Prehnite doesn't like immersion in the sorts of chemical commonly used to clean rocks like oxalic acid, so I read at least.

If you're able to grind a couple of "windows" opposite each other in the hard shell you should have at least some idea. The coarse wheels of a cabbing machine would be the ideal tool for this since they run water over the wheels that both keeps the stone and wheel cool and suppresses the dust but if you don't have access to one then a regular bench grinder might be ok so long as you're careful not to overheat anything and definately wear a dust mask.

Cheers

Thanks fellas, 5 grinder and flap disc it is.

Shep said:

Thanks fellas, 5 grinder and flap disc it is.

Click to expand...

And don't forget the Dust Mask.....

LW...