utah translucent calcite

Quoted text begins.I have heard that you polish it with muriatic acid
End of quote.

Hi Sean, welcome to the StoneList.

I recommend that you don't use Muriatic (Hydrochloric) acid for polishing
calcite (marble) because it is too aggressive. HCl will just strip the calcite
away in solution.

Marble polishing is usually done with Oxalic acid. Oxalic acid reacts with the
calcite (calcium carbonate) to form calcium oxalate. Bonded to the marble
surface, it fills in any pits and transmits light through the surface crystals.

Some more information here:
http://www.rockhounds.com/rockshop/john_betts/clean1.html

Marble polishing is only successful if it is done on a thoroughly prepared
surface. Use a range of wet and dry sandpaper from coarse through fine until the
surface has a dull shine. Apply Oxalic acid sparingly with a damp buff pad or
damp, folded hessian bag. Rub until it smokes. Wash all traces of acid away or
it will burn off the polish you have just produced.

If the calcite is very fragile it would probably carve best with grinding tools.

Regards,
Simon