I came into about 200 Roman Bronze coins and they are a mess. Some are covered in white, tan or thick dirt and crud. The attached photos show one of the best ones in the lot. It’s missing about 20% of the coin and there is a crack between 2 & 3 o’clock on the obverse. 1) I have no idea what this Coin is, where it’s from, who’s on it or anything else about it. if you can identify it please do so. 2) What would be the safest and best way to try and clean the thick dark crud off of the coins? 3) Any way of cleaning the white or tan off of the coin so you can see what the coin is? I’m not sure what the white is, but the tan looks like sand. It does not scratch off with the fingernail. Thank you to all those who offer information on answering these questions.
I have dealt with very dirty and encrusted bulk ancients in the past. Doing a soak in distilled water for a few days and using a soft toothbrush and/or toothpick to gently remove the residue is a good first option, IMHO. After that, a long term olive oil soak is what I would do. Could take weeks to months and periodic monitoring. Have fun!
I've cleaned a bunch like that in the past. as NPCoin said, distilled water to start then oil.. alot of ppl use olive as it's mildly acidic but I find mineral oil seems to work better.
I like to identify my coins in my lifetime. I use a combination of mechanical and chemical cleaning. The coins in the photos here have been placed in a solution of Vinegar and 40 Vol Peroxide. Notice the bubbles that start forming immediately from the surface. The coins must be monitored closely or they may "burn". Removed them and rinse in water regularly. I have several hundred very nice coins that started as uncleaned.
