cleaning a north wales diamond with copper inclusions

Today I found another North Wales diamond on the surface. The main lode mined was copper. The crystal, although only half of it, has what appears to be copper green malacit inclusions in it. The problem is its covered in thick crud wich i cant remove. Ive spent 4 hrs scrubbing it, put it in hot water to try and soften the brown stuff, scrubbed it with salt as an abrasive washed it, left it in bicarb solution just incase and now its soaking again in water. What should i do? How can i get the brown off as it looks like its 'welded' on to it. As you look through the clear parts you see beautiful greens in it. Its really nice.

Any ideas ple

Many thanks

Claire

Put it in concentrated hydrochloric acid for a few days and see what happens. It should not hurt the quartz.

Rock Currier
Crystals not pistols.

It'll sure hurt the malachite though, if it has any exposed surface!

Tim

There is green finally showing through the brown stuff which is proving difficult to scrub off. Im using eithrr salt or sugar as an abrasive, is this ok or is there anything better please?

many thanks
claire