Sunday, March 22, 2015

Kushano-Sasanian coins are kind of interesting

Last week I posted on import restrictions on Roman coins. That post got 13 replies -- a much higher volume than my usual posts. Looking over my earlier posts, I see 16 posts that received zero comments and then one on import restrictions on Egyptian coins that somehow got 12 replies. It seems my readership is mostly interested in Customs issues.

When I started this blog I had hoped to write about computers and ancient coins, but those posts seem to attract little interest. In the past I have asked readers what they want to see here, but have gotten merely generic encouragement.

Wayne Sayles recently blogged about collecting coins that others ignore. I think Wayne is on to something so I will write about that. Lately I have been interested in pre-Islamic coins and have applied to join the Oriental Numismatic Society.

My latest coin is a Kushano-Sasanian bronze of Peroz I from Balkh circa 245-270 AD. The obverse is said to read ΠIPΩZO OOZOPKO KOÞANO ÞOYO (Peroz the great, Kushan king) and depicts king Peroz standing facing, head left, sacrificing over altar and holding a trident in his left hand.

The reverse is said to read OOPZAOANΔO IAZAΔO (Exhalted God) but I don't know how they get that — I can't make out a single letter on any of the examples I've seen! It depicts the Exhalted God (Siva?) standing facing, holding diadem and trident, before the bull Nandi. The bull has very odd feet on this coin and several other specimens that I have seen.

For those interested in provenance and import issues this coin comes from the collection of Robert N. Cook, Jr. of Graham, North Carolina. The collection was largely assembled 50 years ago in Indian and Afghanistan. Unfortunately I have no documentation for this particular coin before a February 2015 auction.

Wayne's post advises you to collect what others are not interested in. This particular coin sold, unattributed, in a lot of 24 Kushan coins that went for $2 each at auction. They buyer flipped it on eBay for 10x that, misattributed as the Kushan ruler Vasudeva. It is likely that these coins will be more appreciated in a few years after dealers start using the new reference, Kushan, Kushano-Sasanian, and Kidarite Coins: A Catalogue of Coins from the American Numismatic Society, by David Jongeward and Joe Cribb with Peter Donovan. I have not seen that work yet but eagerly anticipate publication.

Saturday, March 21, 2015

False patinas

In Classical Deception (page 54) Wayne Sayles mentions the excellent patinas on Sicilian fake coins starting in the 1990s. After his book was published I noticed copies of the coin Sayles used as an example appearing in the printed catalogs of several dealers.

I was wondering recently if hand-held XRF guns could be used to identify real and false patinas and a web search lead me to a five-year-old post on FORVM by Lloyd Taylor referencing a 2009 paper in Mediterranean Archaeology and Archaeometry. The paper is “Ancient Coins and their Modern Fakes: an Attempt of Physico-Chemical Unmasking” by A. M. Mezzasalma, G. Mondio, T. Serafino, G. De Fulvio, M. Romeo, and A. Salici.

They analyze five fake bronze coins. This is the recipe the forger confessed to:

“…one of the most used recipes for fakes artificial ageing utilizes a solution composed by penthydrated CuSO4 [Copper Sulfate] together with HNO3 [Nitric Acid] and NH4Cl [Ammonium Chloride] in distilled H2O [Water]. In this solution, warmed up until 80‐90°C, the just produced fakes (at about 100 °C) are immersed. Such a bath gives them an artificial patina with an “antique green” colour and a deceptive antiquity appearance. Drops of the above CuSO4 solution on clean bronze surfaces may form dendritic structures with the same characteristics of those observed in our fakes.”

Note: the fake BR02, which the authors couldn't identify, is a Himera gorgoneion / pellets.

Wednesday, March 18, 2015

American collectors should comment on the pending renewal of the MOU with Italy

Under Italian law, all antiquities must be registered with the government. Newly found antiquities belong to the government. So if Italians are digging a well and find some old coins, they must surrender them to the police.

Under US law, countries that have a serious problem with looting / grave-robbing / metal-detecting are allowed to ask for a "Memorandum of Understanding" which lists the kind of artifacts being looted. Currently the US and Italy have one and it covers, among other things, coins of Greek Sicily. So Americans can't just bid in British and German auctions for such coins, because without paperwork showing the coins have been on the collector market for years it is against the law to bring them to the US.

The Italians are asking for an extension. The extensions last for five years. The extension doesn't have to cover the same stuff. It could cover fewer coin types or more coin types. If it covered all Roman Imperial coins it would be frustrating, because these coins would be selling openly in many EU countries, but Americans wouldn't be able to buy them.

Some folks would like to see all ancient artifact sales banned. Others feel the sale of common objects like coins and rings is not a big deal. The purpose of filing comments is so that the US representatives don't just rubber-stamp whatever the Italian representatives ask for.

American collectors should read It's Not Too Late on Cultural Property Observer's blog and leave comments for the US Government's Advisory Committee.

Monday, February 09, 2015

You Thought It Was More

Louis Colavecchio with Franz Douskey and Andy Thibault 426 pages. $24.99, $9.99 on Kindle

Louis Colavecchio's book cover describes him as the "World's Greatest Counterfeiter". That seems to be a standard claim for the genre. Who would want to read a book about the 2nd or 3rd greatest counterfeiter?

Colavecchio counterfeited casino chips, not coins or paper money. He seems to have counterfeited a great deal of chips, enough that casinos have stopped using them.

When I read about counterfeiters I want to see a picture of their fake next to an original. As is typical in these accounts, Colavecchio's lacks coin photography or pictures and drawings of any kind. The cover collage depicts seven casino chips, two steel dies for $100 chips, Colavecchio himself, a slot machine, and a pile of gold-colored coins that look like 1 euro pieces. This is disappointing. Colavecchio claims drafting skills and kept a contraband ruler concealed for years while in prison. I would have liked some technical drawings included in the book.

Chapter 1 is about making and selling counterfeit sweaters in the early 1960s. Chapter 2 is making statuettes using lost wax casting. Chapters 4-6 are about managing jewelry stores. Chapter 8 is about making phone phreaker red boxes and telephone slugs. (The slugs were made around 1980.) 10 and 11 are about importing and modifying sports cars. 13 covers jewelry manufacturing. Chapters 14-17 discuss casino chip counterfeiting (70 pages). Chapters 18-21 discuss jail, court, and prison. The other chapters are about who got whacked in Rhode Island in the 1960s and 70s, and why. Actually all the chapters are about crime and women.

Colavecchio's telephone slugs are only mentioned briefly.

The casino chip dies were made using Electrical Discharge Machining, the process called "spark-erosion counterfeiting" in the numismatic trade. (See Max Spiegel's article on NGC to see an example of a collector coin created with spark eroded dies). A 320 ton Mario Di Maio press was used to strike the chips.

Colavecchio forged both metal and plastic chips. A lot of the counterfeiting discussion in the book concerns getting the correct weight and color out of plastic materials. These discussions may not appear important to the coin collector, but recall that the country or rebel province Transnistria recently started issuing circulating plastic coins.

Colavecchio's writing, or perhaps the writing of his two co-authors, is good. I found all the mob and crime stuff presented in an entertaining way. (The typesetting is poor and there are lots of bogus commas and line spacing issues, but that doesn't reflect on the writing.) The book is well worth reading if you like true crime or counterfeiting. Although Colavecchio brags about having secrets the US Mint needed to consult him on, most of the tips, and that he made amazing improvements to his EDM machine, this book does not go into more detail than other books on coin forgery. This is an entertaining story about criminals, not a technical manual.

Thursday, January 22, 2015

Smithsonian now able to digitize 400 numismatic objects per hour

An article by Max Kutner in Smithsonian Magazine discusses efforts to digitize 250,000 bank notes, tax stamps, and war bonds from the National Numismatic Collection.

Twenty people are able to digitize 3500 items per day, suggesting the whole project will take 72 business days. They use a conveyor belt and 80 megapixel imaging system. The team previously had success digitizing 45,000 bumblebees in 40 days.

The cost per object is less than a dollar.

Thursday, December 18, 2014

Fictional bridges on Euro banknotes constructed in the Netherlands


“'The European Bank didn't want to use real bridges so I thought it would be funny to claim the bridges and make them real,' [Dutch designer Robin Stam] told Dezeen.”

(via Marginal Revolution)

Sunday, December 14, 2014

3D coin scans using focus stacking

On CoinCommunity.com, DVCollector shows a 3D scan of an Athenian tetradrachm. He took 56 pictures of the coin, each with a different focus, and used Helicon software to produce an image in extreme focus as well as 3D animation. Impressive!