: Say you had a very rare gold, proof, U.S. Mint medal embedded in a block of Lucite. Would you a) try to dissolve the Lucite in one of the many solvents mentioned in previousE-Sylum posts (glacial acetic acid, acetone) or online (dichloromethane, chloroform), b) try to freeze it in liquid nitrogen until it cracks, which has also been mentioned, and/or c) take a hammer toit (also mentioned at one point in The E-Sylum)?

: None of the above. You would send the medal to NGC's Numismatic Conservation Service, wait for a couple months while they use their proprietary magic, and then smile broadly whenthe medal comes back as if it had never been entombed!

A few months ago I had the opportunity to acquire a very rare gold Adams Academy medal, which was struck by the U.S. Mint in the late-19th century, and is listed as Julian SC-1. It was one of atotal 17 struck and only the second example to make it onto the market, the first being the example that Jonathan Brecher bought on eBay about 10 years ago (for $65!). This second example came withan engraved silver running award to the same recipient, but unfortunately, both were embedded in Lucite blocks. Jonathan also discovered this second Adams Academy piece and we worked out a trade foran equally rare, gold U.S. Mint medal - more on that below.

After reading the many earlier E-Sylum entries on Lucite removals and doing some online research on the underlying chemistry and possible solvents, I tracked down a technical serviceengineer at Mitsubishi Chemical, which had acquired the Lucite business in 2009. He felt that it would be very difficult to remove anything cleanly from Lucite and suggested I simply take a hammer toit. Hmmm...gold, proof...seemed risky. And my wife wasn't too keen on having any of the various possible chemical solvents in the house, especially chloroform. So, I contacted Danielle Caffrey and DaveCamire, the head of NCS, and decided to send them both medals.

As you can see from the photos, both the gold and silver medals came out great. Even if I knew what specific solvents and processes they used, I would still recommend using NCS for anythingvaluable, as they know what they are doing.

The trade, by the way, involved a handful of medals, but fundamentally boiled down to this rare Adams Academy medal for an equally rare, gold Boston Latin School Derby Medal (Julian SC-10), alsostruck by the U.S. Mint. Jonathan had had to pay a bit more for his second example, around $150 he said (!), but as I had acquired my two Derby medals on eBay for $41 and $210 some years ago, andthere are no modern sale records for either of these rare medals, it seemed like a pretty fair trade.

To read the earlier E-Sylum articles, see:
EXTRACTING COINS EMBEDDED IN LUCITE (http://www.coinbooks.org/esylum_v09n03a21.html)
EXTRACTING COINS EMBEDDED IN LUCITE (http://www.coinbooks.org/esylum_v09n04a22.html)
ADAMS ACADEMY U.S. MINT MEDAL DISCOVERY (http://www.coinbooks.org/esylum_v11n03a13.html)
HOW TO EXTRACT A MEDAL FROM A BLOCK OF LUCITE (http://www.coinbooks.org/esylum_v11n21a13.html)
MORE ON REMOVING COINS AND MEDALS FROM LUCITE (http://www.coinbooks.org/esylum_v11n25a16.html)
MORE ON COINS AND MEDALS EMBEDDED IN LUCITE (http://www.coinbooks.org/esylum_v13n40a14.html)
NGC NUMISMATIC CONSERVATION SERVICES (http://www.coinbooks.org/esylum_v19n52a16.html)