A highly stylized type with hole. This appears to be a marble type stone; these are mentioned in Wang Yu-Ch'uan ("Early Chinese Coinage") as being found in archeological digs. Here a simple angled form suffices and no attempt is made to even cut a groove or to imitate the teeth of cowries. These come in varied sizes and some have grooves. 19 x 19 x 7 mm
Moneta Library has articles on Cowries to VIEW and DOWNLOAD:
The Worlds's First Money, Chinese Cowries and Their Imitations - by Ted Puls: The Worlds Oldest Money Cowries Ted Puls
Cowries - Bob Reis: COWRIES Reis
Origin of Cowries in Ancient China - UofPa: Origin of Cowries in Ancient China
Metallic Cowries - Royal Asiatic Society: Metallic Cowries - Royal Asiatic Society
Nice Video on Cowrie history: http://tinyurl.com/CowrieVideo
An excellent article in ANA's "Numismatist" magazine, Oct 2017 > http://onlinedigitalpublishing.com/publication/?i=440085&ver=html5&p=40
SEE how far back in time decorative sea shells were important to prehistoric man at his : https://www.sciencedaily.com/releases/2009/05/090505163021.htm
Interested in Primitive Money? Then check out this YouTube video created by Kagins Auctions featuring Bob Leonard and Charles Opitz upon the massive sale in March 2021. Click this: https://www.youtube.com/watch?v=9MIKxfbAaZg
These come in varied sizes and some have grooves.