Watch List notes:

THAI KINGDOMS: AR shell money (93.81g), cast to approximate 37 massa or 3½ Spanish reales in value; this example is a de-acquisition from the Money Museum of the National Bank of Detroit, a very large example! ex Charles Opitz Collection. Sea shells used for casting were carefully chosen to produce a denomination sequence. The wear typically found suggests they circulated quite a bit; that and "shaving" could account for weight variations. Specimens seen include bottoms with pits where metal was removed, dabs of metal added to adjust the final weight, and cooling lines as on sycee. Singh and Mitchiner catalog more symmetrical "mound bidor," with weights related to a Kati system convertible to Spanish silver - possibly a later and/or local version of this early shell currency. This example is the plate coin in "An Ethnographic Study of Traditional Money: A Definition of Money and Descriptions of Traditional Money" by Opitz.

Estimate: 150-250 USD