Restoring a Beautiful 1949 Half Penny – An Error?
A spectacular example of toning recently returned to TEC, after having been removed from the slab and sold at auction. So I did something I’ve been meaning to try out. The coin was degreased and given a coating of VerdiChem.
After the VerdiChem
Above is yours truly screaming “OMG” after the fact. No one wants to destroy colour, but that is exactly what it looks like.
The Return of Colour
A couple of days later, some of the colour returns. I suspect the VerdiChem adds a nanolayer of coverage to the coin’s surface, which impacts upon the light refraction and colour we can observe. The physics of toning can be read of in this link.
I am unable to determine if a corrosive alkaline substance removes stable oxidation, as well as dust and grime. That would appear logical. However, image comparison and a review of Sunnywood’s Color Classification chart below suggests that the reverse rim is now advancing to I and J – the yellows.
A Multi Year Proof Penny Comparison
This natural progression of colour toning is illustrated in the 1958 Proof Penny de-slabbed in 2021 (below left). Two years later it has taken on similar 2nd Cycle colours I through K. The heat and humidity of the Northern Territory is a suspected accelerant in this process. I’m waiting to see reds through emerald green.
Such natural toning can be compared to the following example, located on Ebay. Geoff Heidemann of Cockatoo Coins suggests that a gas stove was used to create these pastel colours. Compare the coin below to the previous illustrations – note the soft, wishy washy borders between the various colours on the reverse.
Watch This Space
We’ll review the 1949 half penny in a year for further colour development. Hopefully this article has helped illustrate the progression of toning and will assist collectors in choosing the real deal. There’s plenty of doctored stuff out there. The author’s professional interest is in understanding whether restoration regresses a coin’s natural toning, does nothing or accelerates changes to the toning.