Lying on theThai  coast, close to the Cambodian border, the city of Chanthaburi has long been known for its precious stones. In 1408, Chinese traveller Ma Huan made the first known reference to the area's natural bounty: Siam rubies, sapphires and other gems.

This is also where Chinese and Vietnamese first settled in the late 1700s, when Bangkok, 250km to the northwest, was made the Siamese capital. Then came a Chinese goldsmith whose invention is still sought after today.

In the 1850s, a man named Tek plied the waters of the South China Sea before disembarking from his junk and clambering ashore in Chanthaburi. Here, he opened a gold shop and crafted a ring formed of four interlocking loops: a puzzle, or magic, ring. Once taken apart, the four bands of the ring hang loose but remain connected by one loop. How to reassemble it is the puzzle.

Today, a great-granddaughter of Tek, Montha Pumipark, is continuing his work. In public, the septuagenarian is known as Khru (which means "teacher" in Thai) Montha. At 13, she started her apprenticeship in creating puzzle rings, learning from her parents. She was not the family's only student, but her older brother has died and her younger brother has had to retire due to deteriorating eyesight.

Armed with a dozen pliers, two hammers and other tools, Montha crafts gem-studded interlocking gold rings shaped like a crab.

"We undertake every assignment with pride," she recently told Living Thai, a magazine of the Support Arts and Crafts International Centre of Thailand. "We are proud of our ancestral legacy. We put our hearts into our work - every step and every detail."

It takes at least 10 days to produce each ring, all of which are made to order. Depending on the gold and gems used, rings cost from 9,000 baht (HK$2,000) and up, and each comes with a CD explaining how the piece can be reassembled.

Rings also come in the shape of dragonflies, mangosteens, fish and snakes, and the craft is likely to stay in the family for some years yet: Montha has passed on the craft to her son, Montri (email: [email protected]), and nephew, Chai-anantabhumi, who specialise in shrimp and crab rings, respectively.


Tricks and stones: the gem traders of Chanthaburi