Greek Letter Stigma

During research for the Numismatica font, I became concerned about the limited understanding some numismatists have of the Greek letter Stigma. This note explains the letterform and why there may be confusion; in this article, I use capitalization to differentiate case of Greek letterforms, e.g., Sigma and sigma.

1	10	100
2	20	200
3	30	300
4	40	400
5	50	500
6	60
7	70
8	80
9	90

My concern is due to an assertion by Kevin Butcher in Roman Provincial Coins that the numeral six in Greek dates was the character sigma¹, which he shows as ς , the lowercase final form used only at the end of a word in modern Greek. I discussed my opinion with several scholars and consulted authoritative texts. I believe Butcher is in error because he confused a lowercase final sigma with Stigma

. While the shapes of those two letterforms are very similar, lowercase Greek letters were not developed until the Middle Ages. Thus, one cannot use the relatively modern letterform to argue that Sigma was used as the number six in archaic, classical or Hellenistic coin legends. Also arguing against Butcher's assertion would be the negative consequence of using Sigma to simultaneously represent 6 and 200.

Perhaps one source of confusion might be that while digamma occasionally appeared on coins as

, identical to the common square Sigma², the engraver's intent to represent digamma or Sigma should always be clear from the context. Adding to the confusion among numismatists was the use of a capital Latin

to represent

by several recent authors³, lending false credence to the idea that Sigma represents numeral six. While the

letterform was used as Iota, Beta and Sigma, I find no evidence it was employed as Stigma or Digamma on archaic, classical or Hellenistic Greek coins, but

was used to indicate officina six on Roman coins.

G. F. Hill differentiates Digamma

and Stigma

, and tells us the

was used only as a numeral⁴; it always represented the number six and its name evidently coincides with its early origin in a Sigma-Tau ligature⁵. The terminology confusion between Digamma

and Stigma

appears to be caused by their common numeric value and that

supplanted

. We know Digamma

had its origin as a borrowed Semitic letter⁶ for use as a numeral but it also was used to represent the sound "vau" or "w". Digamma

was used as both letter and number until its eventual disappearance.⁷ I have not seen Digamma

used on coins in its numeric sense (and would be happy to learn of such use in any coin legend).

The name Stigma for

may have as its origin the vocalization of the Sigma-Tau ligature ΣΤ, whose appearance is similar. This is consistent with present-day Greek usage; while modern Greeks normally employ Arabic numbers, they also use the old Greek non-zero system, and readily recognize

(which they call Stigma) as the numeral six. For example, the old Greek letters are used to number pages rather like Roman numerals are used in English⁸, and to number laws in legislative documents. The font specification community, which includes and relies heavily on Greek academic specialists, uses the name Stigma for

in the Unicode specification.⁹

On some Greek coins, Stigma takes the stylistic form seen on the following coins, very similar to the

used on Vardanes II Tetradrachms Dated 366.

Chris Hopkins
23 April 2001 (amended 26 May 2006)
____________________
Notes:
1. Kevin Butcher, Roman Provincial Coins: An Introduction to the Greek Imperials (1988), p. 114.
2. G.F. Hill. Ancient Greek and Roman Coins (Argonaut, 1964 reprint), p. 215. Hill's summary of Greek letterforms has been invaluable in preparation of the Numismatica font. Without naming them, he discusses Digamma

and Stigma

as two different characters.
3. For examples where

is given instead of the correct

, see D.R. Sear, Greek Coins and their Values, Vol. II (1979), p. xxxvii and Greek Imperial Coins and their Values (1982), p. xxv; J.M. Jones, A Dictionary of Ancient Greek Coins (1986), p. 158; Wayne Sayles, Ancient Coin Collecting, vol. I, p. 98 and vol. II, p. 13.
4. Hill, op. cit. While Hill's statement is true for ancient usage, there are more modern texts (1400s through 1700s) where a lowercase stigma was used in place of the lowercase sigma-tau ligature in words such as Constantinople, Κονςαντινοπολη not Κονσταντινοπολη (Michael Everson, "Additional Greek characters for the UCS," Working Group Document ISO/IEC JTC1/SC2/WG2 N1743, 25 May 1998, p. 1.)
5. Greg Flegg (ed.). Numbers through the Ages (1989), p. 88. Chicken or egg: none of the authors discusses whether the ΣΤ ligature appeared and acquired the name Stigma, or the ligature was used because of the letterform's already established name.
6. Karl Menninger. Number Words and Number Symbols (1970), p. 270. Qoppa = 90 and Sampi = 900 were also borrowed Semitic letters.
7. Herbert Weir Smyth, Greek Grammar (1956), p. 8. Digamma

presumably fell into disuse about the time Athens adopted the Ionic alphabet in 403 B.C., but it disappeared gradually, and was used in Boeotia as late as 200 B.C.
8. Georges Ifrah. The Universal History of Numbers from Prehistory to the Invention of the Computer (2000), p. 220.
9. Unicode Consortium. "Greek and Coptic, Range 0370-02FF," The Unicode Standard, Version 3.0 (Addison-Wesley Developers Press, 2000).

Greek Letter Stigma

A clarification of its use as a number