How to Remove Hardened Clay off Apatite

I've collected a cluster of clear apatite crystals on a feldspar matrix from Mt. Mica. All of the apatites are covered in hard brown clay. I have had a little success in scraping the clay off with a razor, but I don't want to scratch the crystals. I've tried soaking it in soapy water for a week and soaking a similar specimen in a bath of super iron out with no success. The super iron out only made the clay turn green. Any suggestions?

Hi Thomas

Try letting the clay dry out real good, then wetting it for a day, and get your self a "Mystic Cleaning Gun" from the American Nigara Corp.
The spray can be adjusted from a fine pinpoint spray that will sting your fingers real bad to a gentle wide mist that wouldn't hurt your eyeball.
You'll find a few posts here in mindat about using them. Just use water in it, it will even clean in the deep cracks.
Cleaning with a razor, dental picks or other such things will only damadge and scratch your specimen's.
Another thing that sometimes works is denture cleaning tablets, if the clay isn't too hard.

KOR
Wayne Corwin

PS: Looks like you'll have a nice specimen

You might try some hydrogen peroxide, hair bleach grade. I have had some success listening up clays with that on occasion, but there are many different kinds of clay.

Rock Currier
Crystals not pistols.

Someone told me that they had good luck with trichlorethylene, although I am not sure of a source for it and have never tried it. Like Rock says though there are many kind of clay and it may not work on this one.

I think I'll try the hydrogen peroxide first only because that's what I have most readily available. I'll try getting one of those mystic cleaning guns when I get a chance. Thanks for all the responses!

Looks like a cookeite coating which would need air-abrasive cleaning. Hope I'm wrong and the previous suggestions work! The gun is worth the money whether it works or not in this case.

Hydrogene Peroxide is a good solution but you need a stronger concentration as this for hair bleaching. Unfortunately hydrogene peroxide is also used by terrorists for constructing bombs. Therefore it will be hard to receive it.

I got good results by using Dithionite in a bufferen solution. The clay is stabilised by the iron ions. The dithionite solves the iron in the clay and makes the clay soft and friable. After that you can remove it by an old tooth brush.

However, as Rock Currier said: There are different kinds of clay.

Uwe Ludwig

I am looking forward for cleaning these vissuvianite minerals from Zagi's mountain from North west of Pakistan.
Stay Blessed,
Ali

I am looking forward for cleaning these vissuvianite minerals from Zagi's mountain from North west of Pakistan.
Stay Blessed,
Ali