


This is one of the most interesting date of French Indochina silver coins, which was debased the silver from 0.835 fineness to 0.400 (dropped 52%) but weight increased from 2.75g to 3.1g for 10 Cents (KM# 14), and 5.4g to 6g for 20 cents (KM# 15). People in Indochina against it due to the low content of silver, and finally 0.680 fineness coins were issued (湯國彥 et al., 1993, p.68). Consequently, 10 Cents is scarce and 20 cents is very tough to locate, especially in mint states. I cannot find any information about the recalled/melted for both denomination of 1920, but from the scarcity of both coins, recalled or melted were possible. The actual rarity level is far higher than Krause SCWC suggested (no one update this part for several years...).
The characteristic of both 10 and 20 cents are weak struck, and a bit crude particularly the edge; without mint marks and without fineness indicated. Usually some sellers/collectors grade the
mint states specimen as
almost uncirculated because of its weak struck on both obverse and reverse (look likes very fine to good very fine details;
this case is similar as British Edward VII coins particularly large coin such as Crown or half crown, obverse side looks like worn but actually it's mint states). What's the different within weak strike mint states and circulated condition is the 'worn' area is still with original mint luster, whereas circulated coin with darker mark or no mint luster on it, or extra 'bright' (rub) on worn area [
not cabinet friction]. For this 10 cents example, this is clearly a circulated coin with little wear, although it looks like moderate wear, whereas the 20 cents here is mint states, but look likes VF details with original mint luster.
Besides 10 Cents and 20 Cents, silver Piastre (KM# 5a.3) were also struck in San Francisco as well, i.e. without mint mark. It's interesting to know why the silver content of Piastre was not debased whereas the 10 and 20 cents debased in silver fineness. Anyone can tell?
Krause SCWC states that without mintmark are either strike in Hanoi, Vietnam or Osaka, Japan. However, the coins were strike in San Francisco should be without mint marks except "S" on copper-nickel 20 cents 1941 reeded edge non-magnetic coin.
ReferencesKrause & Mishler,
Standard Catalog of World Coins 1901 - 2000. 2008 (35th ed.), 2009 (36th ed.), 2010 (37th ed.), 2011 (38th ed.). Krause Publication.
Semans, Scott,
VIETNAM CASH COINAGE 970 - 1945, coincoin.com.
湯國彥
et al., 1993,
越南歷史貨幣, 第一版, 中國金融出版社
AcknowledgementThanks to Mr. Bruce Smith for the discussion to confirm the mint area of the coin.