Tuesday, October 30, 2018

Laser cleaning of ancient coins

Briefly noted: An 8-year-old paper by Eleni Drakaki, Andreas Karydas, et al: “Evaluation of laser cleaning of ancient Greek, Roman and Byzantine coins”. Successful results are claimed, sometimes in conjunction with mechanical cleaning.

The article is a followup to an earlier paper, “Laser cleaning on Roman coins”. The image for this post comes from the first paper.

Monday, September 24, 2018

Three-dimensional reconstruction of Roman coins from photometric image sets

Three-dimensional reconstruction of Roman coins from photometric image sets”, a 2017 Journal of Electronic Imaging paper by Lindsay MacDonald, Vera Moitinho de Almeida, and Mona Hess.

The present study combined two datasets representing the surface topography of the two Faustina coins (Fig. 1). First, they were scanned by a 3-D color laser scanner, producing a point cloud of the surface shape. Second, they were photographed in an illumination dome with directional lighting. The two representations were combined to produce a digital elevation map (DEM) of each coin with the accuracy of the scanner and the fine detail of the photography.

Tuesday, September 18, 2018

The Insane Million Maker Master Counterfeiter

Good documentary storytelling on counterfeiting: Snap Judgement recently made a 22 minute segment about Frank Bourassa, a Canadian who counterfeited a quarter of a billion US dollars in twenties in 2009.

I calculate that $200,000,000 in $20 bills would weight 10 tons and would completely fill a 12' moving van.

Friday, September 07, 2018

NGC population reports for graded ancient coins

Catalogers of high grade modern coins often boast about coins having only a few specimens, or even no specimens, known in a higher grade.

Ancient coin catalogers will sometimes say "finest known" but they rarely say things like "only a population of 43 coins better".

On NGC's slab verification pages, for example https://www.ngccoin.com/certlookup/4629247-016/NGCAncients/, there are no population reports comparable to modern coins. That page says "Total Graded by NGC: Not Available".

Yet I noticed the Heritage Auctions web now includes NGC Ancients population reports. I noticed this watching their Long Beach auction yesterday. Here is an example from a recent Heritage online-only auction: https://coins.ha.com/itm/ancients/g...m-9h-ngc-ms-5-5-3-5-test-cut/a/231836-61011.s . The auction listing displays the slabbed population with the grade of the current lot highlighted in yellow.

Here is the owl population as of September 7th 2018:

The auction house gives an NGC population report and includes the count ranked star (= "impressive"). They don't mention "fine style" or "test cut" or the x/5 ratings. This particular lot has a huge test cut that doesn't make it into the numerical chart.

I was curious to see the single starred "Choice MS" example in the above population report. It is https://coins.ha.com/itm/greek/anci...22-gm-5h-ngc-choice-ms-5-5-5-5/a/3066-30035.s, and it sold for $36k last month.

Monday, August 27, 2018

Replica hobo nickels

Is anyone familiar with Chinese hobo nickel replica maker Gyphongxin? The e-Sylum discussed Chinese hobo nickel replicas but I still meet advanced collectors who do not know the scope of it.

I purchased the "hobo dime" above with the Medusa skull design last year. It looks like a 1916-D. Often the creations of the artist (or artists?) "Gyphongxin" duplicate award winning hobo nickels but I haven't found the prototype for this one. A store on Alibaba.com is selling these for $1.70 and they say they have 9837 pieces available. The seller also has one with a 1916-S reverse with 9995 available.

In hand the coins don't look particularly great. Other Chinese replicas do look great. I recommend anyone interested in the Chinese replica coin production quality listen to Charles Morgan interview Beth Deisher on the CoinWeek podcast.

There is a new wrinkle in how the coins are being shipped. The half-dollar at the top of the page sold on eBay for $4 with free shipping. It shipped from China to the nation of Georgia. (Not the US state, the former Soviet republic.) A different shipper slapped a sticker with a return address in Tbilisi over the first sticker. This process caused the replica to take six weeks to arrive. Why is the seller is willing to pay for double postage and send the coin around the world the long way? I suspect US Customs authorities are looking for and stopping these replicas.

I recommend everyone check out this Alibaba.com store. Perhaps the ancient Greek and Roman coins won't fool you. Perhaps the US coins or the world silver won't fool you. There are a few things in this store that look very good in a photo and sell for a dollar or two.

Friday, August 17, 2018

The Feather Heist

Good reporting on museum security: This American Life recently made an hourlong episode about the 2009 smash-and-grab burglary at the Natural History Museum, London. Bird carcasses and feathers worth more than $1,000,000 on the fly-fishing black market were stolen. Some have been recovered.

Thursday, July 26, 2018


If your are interested in coins there is little to see except the Numismatic Museum. The museum is a single room in the Central Bank of Iceland building. The room is open weekdays 1pm to 4pm. It is across the street from the Harpa concert hall and borders the park with Einar Jónsson’s statue of Viking settler Ingólfur Arnarson.

The highlights are Halldór Laxness’s Nobel Prize medal and Thröstur Magnússon’s plaster design for the 100 kronur coin along with an obverse die.

There were no Viking coins on display.

Iceland’s 1930 Althing commemorative coins were on display. I had seen photos of these coins but the real ones look much more impressive than the photos.

I would have liked to purchase collector coins. (Some central banks, such as Ireland, have a retail window for collectors.) The guard at the Iceland central bank did not know about coins and the curator of the museum was on vacation at the time of my visit.

Other than the museum there is not much coin-related to do in Iceland.

Coins are still in use but I wasn’t getting many of the smallest denominations in change. At the nearby Landsbankinn bank branch I found a vending machine for coin rolls. The machine is labeled myntrullur which I believe is the Icelandic word for “coin rolls”. It seems to be a rare word — a Google search did not find a single instance. (Web searched found 20k examples of the related Norwegian word myntruller.)

I went to the Kolaportið flea market to look for obsolete coins. I found a booth stocked with stamps and banknotes but not coins. There was a booth with miscellaneous circulated coins of many countries, mostly Iceland, to pick from for a few kronur. That booth also had a single partially-filled coin album with holes for all of the coins issued by Iceland up until 1970. This album would have been an interesting numismatic souvenir but soft PVC held the coins in place and many had turned green.

Another booth at the flea market had a few uncleaned Roman coins. These were not Icelandic finds and the vendor wanted the equivalent of $30 each for them.

Many of the gift shops in Iceland have sets of obsolete coins. The coins for sale are exactly what is offered by http://www.lucky-coin.com/coins although the prices are about 3x what is listed on that site. The frustrating thing about these sets is the mixed condition of the coins. There will be nice AU-grade coins alongside cleaned G coins. It would take several sets together to make a nice set. Also, most of the holders are wrapped with soft plastic so there may be PVC concerns.

There is an Iceland Numismatic Association but they don’t meet in the summer. I also tried to contact two eBay sellers based on Reykjavic but there were out of town.

Iceland's circulating coins are nice. They depict fish. Coins aren't issued every year. Some of the coins I received in change were in great condition even though dated 2011 or even earlier.

Sunday, April 22, 2018

Anti-pollution medal by Vasco Berardo

Another anti-pollution art medal.

Portugal, 1974. Vasco Berardo (1933-2017). 95mm. Mintage 400

Obv: Poluição / Cavaleiro do Apocalipse (=Polution / Horsemen of the Apocalypse); Bust wearning gas mask and headphones; demon birds behind; artist's signature below. The entire field engulfed in poisonous vapors.

Rev: Caped rider wearing armor and shield on left arm, holding wrench in right hand, riding right on armored horse motorized horse through wisps of pollution.

From a series of six horsemen. Pestilence is one of the original four horsemen described in the Biblical book of Revelation. In Berardo's vision the horsemen are Peste (Plague), Fome (Hunger), Poluicao (Pollution), Morte (Death), Guerra (War), and Droga (Drugs).

Friday, April 20, 2018

Anti-pollution medal by Isolino Vaz and Luciano Inácio

(Image from medalhasportuguesas.wordpress.com, a Portuguese medal blog.)

For Earth Day (April 22) here is an anti-pollution medal from my small art medal collection.

Portugal, 1972. Designer Isolino Vaz (1922-1992), Engraver Luciano Inácio. 80mm, 272g

Obv: Poluição (Pollution); bust of a malnourished and bald figure, turned to the right, with the hand on the forehead in sign of agony.

Rev: Girl with braids and school gown kneeling plants a tree in the ground. Next to you a shovel. Behind, four flowers, two on each side and in the sky are three stylized figures of birds.; Salve Mos o Mundo; Valadares - V. N. De Gaia / 30-VII-1972 (Save the World; Valadares - Vila Nova de Gaia - July 30 1972. Valadaras was a parish in Gaia city.)

Edge: 147 / 500

Note: This medal was executed in the workshops of João Baptista Cardoso, for the initiation of the Promoting Committee "Recordar é viver" (Recall is living), formed by former students of the primary schools of Vila Nova de Gaia. 500 examples were made in bronze and another 20 in silver, distributed by the "Galeria Arte e Medalha", in Oporto.

Friday, March 23, 2018

Ball Terminal

Here is the inscription on a coin of Mithradates the Great, circa 85-75 BC. (Not mine. A dealer photo.)

The characters have circles at the ends. If the ends had been lines we would call them "serifs". Many years ago I tried to learn the term for characters with circles on the ends but eventually gave up. Today, while reading an article on the typography of James Mitchener's novel cover art, I stumbled onto the term “ball terminal”.

Exactly what I was looking for. Now I can search for this term ... and find very little.

Thursday, February 01, 2018

Recording provenance in the blockchain

An October 2017 article by Peter B Campbell in The Guardian, “Archaeology and blockchain: a social science data revolution?” discusses using blockchain, the computer technology that ensures Bitcoins are not counterfeited, to record provenance data for antiquities.

Campbell is an archeologist and his article mentions Islamic State and blood antiquities. Those claims might be overblown but the technical scheme described by the article seems workable for medium and high values items. The startup Kapu already conducted a test of using a digital 'coin' to create a provenance ledger.

Were an artifact to have a blockchain record, each time it crossed a border or was sold to a new collector the record could be updated to show it was legitimate. Conversely “blood antiquities” would have no record and faked records could not be manufactured as they often are today. Border security could then compare records of artifacts declared at customs to databases such as INTERPOL.
Some of the ideas, like swabbing antiquities with synthetic DNA, seem fanciful. The basic claim seems solid. Using blockchain technology for art isn't science fiction. An article by Jason Bailey on Artnome explains that the technology is already in use for proving ownership of digital artworks. Verisart and Codex are startups in this space. They hope to convince auction houses to use their technology to record sales.
Codex Protocol is designed as industry infrastructure for art and collectibles. So it's fine wine, classic cars, jewelry, fine art, anything else that sort of fits into that category of items.
For ancient coin collectors one problem is that we would like to be able to prove ownership before 1970, or before the 2007 agreement between the United States and Cyprus. These technologies are for recording transactions now, not 50 years in the past. I would be interested to learn what the legal community thinks of these things.

The SciTech Lawyer, a publication of the American Bar Association, just published an article on that very topic. Unfortunately for me, law professor Derek Fincham's article “Can Blockchain Technology Disrupt the Trade in Illicit Antiquities?” is not available to non-subscribers.

In the comments section, discuss if you would be interested in using blockchain to record your ownership of coins, and if you would pay a premium to know the previous owners of a coin back to 2019.