How to Identify the Siam Tin Pot Duang / Porcelain Gambling Token

What It Is

This entry covers two distinctive forms of pre-modern Siamese exchange media. "Pot Duang," often called bullet money, was Siam's traditional bent-bar currency made of tin or silver, used for centuries before machine-struck coinage was introduced. Porcelain gambling tokens were small ceramic pieces produced mainly by Chinese-run gambling houses in 19th-century Bangkok, used informally as small change or gaming chips rather than official currency. Both forms circulated alongside one another for a time in 19th-century Siam, reflecting a monetary landscape where official royal currency and informal, privately backed tokens both played practical roles in daily trade.

Design & Marks on Pot Duang

Pot Duang consists of a thick bar of metal bent around into a rounded, bullet-like lump, stamped on its visible face with one or more official punch marks. The most notable of these is the chakra (discus) symbol representing the ruling dynasty, along with a smaller personal mark of the issuing king or minting official.

Design & Marks on Porcelain Tokens

These are flat, thin discs — usually round, though occasionally other simple shapes — made of glazed porcelain in various colors, stamped or painted with Chinese characters, simple pictorial designs, or numerals identifying the issuing gambling house or its assigned value. No royal marks appear, since these were privately issued.

Size, Weight & Material

Pot Duang pieces vary by denomination, generally ranging from about 10mm to over 20mm across the rounded body, made of a tin-lead alloy or silver depending on the issuer and era, with silver examples historically more valuable than base-metal tin versions. Porcelain tokens are thin and lightweight, usually 15-30mm in diameter, made of low-fired glazed clay or porcelain.

Identifying Marks & Where to Find Them

On Pot Duang, the combination of the dynastic chakra stamp and a secondary royal or mint symbol identifies the reign and sometimes the specific issuing authority. On porcelain tokens, the Chinese characters or pictorial motif identify the specific gambling house, plantation, or region that issued them, and these have been extensively cataloged by specialist collectors.

Telling These Apart from Similar Items

Pot Duang should not be confused with ordinary cast metal ingots, since its bent-bar shape and official punch marks are unique to Siamese currency. Porcelain gambling tokens should not be confused with true coinage, since they carry no national or royal insignia and are made of ceramic rather than metal.

Judging Condition at a Glance

For Pot Duang, check how clearly the punch marks remain and whether the metal shows cracks or heavy corrosion, since tin alloys can pit over time. For porcelain tokens, check the glaze for chips, crazing, or fading of painted or stamped designs. Well-preserved tokens retain a glossy, even glaze and legible markings, while worn examples often show dulled surfaces and chipped edges from handling and gaming table use.

Authenticity Red Flags

Because both categories are collected today, modern reproductions exist. On Pot Duang, be wary of stamps that look too crisp or uniform, since hand-punched marks on genuine pieces are somewhat irregular, or metal that seems too light or too clean for its apparent age. On porcelain tokens, watch for new, machine-uniform glazing or printed rather than hand-stamped designs, which suggest a modern reproduction rather than a 19th-century original.