Several mentions have been made in the blogs recently of a new term applied to the surface of Lincoln cents: woodgrain. The term is apt. The illustrated surface of an 1981-D cent does indeed look like the graining in wood. While this may be considered an anomaly of toning, instead it is an anomaly of the metal composition. It is an error in mixing of copper and zinc.

The term 'woodgrain' is not new to numismatics, although it probably is new to Lincoln cents. I checked my files for more information. I found a comment by Alan Herbert in Numismatic News 2/16/93 that reads, "It is a peculiar effect found on many of the early Lincoln cents which after a time appear similar to the typical wood grain, with alternating light and dark streaks across the coin..." And in Numismatic News 3/26/1996, F. Michael Fazzari wrote about improper alloy mixing with resulting streaking (but without using the term 'woodgrain') and notes these are often found on, and helping to authenticate, 1908-S, 1909-S VDB and 1914-D cents. He showed a photomicrograph of the 08-S Indian cent.

"Woodgrain" is an old term, used years ago to describe Indian Head cents.

The phenomenon is quite often seen on early cents from the San Francisco Mint, from 1908 on, and I first heard of "woodgrain toning" as a means of authenticating 1908-S, 1909-S Indian cents, 1909-SVDB cents and 1909-S Lincoln cents at an ANA Summer Seminar counterfeit detection course in 1976.

Use of the term "woodgrain" in reference to striated toning on bronze and copper-nickel coins is not a recent development. I've been using this term in my writing for so long that I no longer remember whether I was the first or picked it up from someone else. As an example, I'm attaching my column from the August 2002 issue of The Numismatist.

For the period described, however, ‘S’ Mint cents are seldom seen untoned. The only issues commonly encountered in that condition are the widely hoarded 1909-S cents, both with and without the designer’s initials “V.D.B.” Subsequent dates through the mid-1920s are typically toned to various degrees, though many have survived with partial mint color.

Examples having just light toning often display a pattern of tan or light brown streaks across obverse and reverse, the so-called “woodgrain” pattern. This resulted from impurities in the alloy or concentrations of pure copper that did not properly blend with the 5% tin and zinc added to it. When these less than perfect ingots were rolled into strip, from which blanks would later be punched, the concentrations were flattened and stretched into the patterns seen on the finished coins. Invisible when first struck, these flaws appeared only after the coin was exposed to atmospheric agents that caused the copper concentrations to tone more quickly than the properly mixed portions of the planchet.

Woodgrain toning is commonly seen on ‘S’ Mint cents through 1923-24, after which time it is encountered only occasionally.

There seem to have been slight differences in the bronze alloy over the years. While these differences were probably minute and virtually undetectable when the coins were first struck, over a period of decades Indian cents from different alloy mixes have toned somewhat differently.

Thus, an uncleaned, undipped Mint State red and brown bronze Indian cent of the 1864 to early 1870s years (and also 1908-S and 1909-S, but not the Philadelphia coins of those later years) is apt to have a “wood grain” effect to the toning, with streaks or “pellets” of brown toning, elongated, over yellowish-red mint red background, these streaks being oriented in a specific direction (caused by the distending of the minute alloy differences during the planchet strip rolling process).

The same wood grain effect is seen among certain dates of Mint State red and brown two-cent pieces. To my eye, this type of red and brown wood grain toning is very beautiful. Chris Pilliod seconded this sentiment, noting: “I agree and find these pieces very attractive, but the grading services apparently do not.” [

Dick Johnson's article on woodgrain Lincoln cents was fascinating. The term "woodgrain" has been used by collectors of early American coppers for many years. In the case of early coppers the woodgrain effect is caused by "bad copper", that is, copper with significant impurities, which create the woodgrain feature when the coin is struck. About a month ago I received in the mail a 1837 N15 large cent which has significant woodgraining. The woodgrain wasn't mentioned in the dealer's list description, but I was glad to get it as I had always wanted one.

It's the discovery Sheldon-15 that I got out of the Van Cleave sale in 1986. There will be a display of the 1793 S-15 at next month's EAC convention. This is the second rarest collectable Sheldon variety with twelve known examples (two are in museums). Eight owners have agreed to bring their S-15s. The one owner that I have not been able to trace is the person who got the FR2 coin out of the Robbie Brown II sale in 1996. The buyer was Larry Briggs - a dealer from Ohio. I don't know whether he bought the coin for a customer or himself. I would like the owner to contact me at j_neiswinter@hotmail.com. to see if he would be interested in exhibiting his coin.

I've seen the "woodgrain" term used in Canadian and British circles, too.