​The rough stone especially corundum from the mine or from around the world are brought to Thailand's factory to enhance quality, cut and polished followed by sorting by the expertise. 

Trat is the home of renowned Siamese Ruby. Borai, Trat Province, near the Cambodian border, on the Eastern Seaboard of Thailand. It had been a land of plentiful gemstone resources, begun to do gems mining since 1973. Locals refer to rubies as "tabtim", which means "pomegranate", because the red gems closely resemble the bright red seed pods of pomegranate fruit. The ruby in Borai are in residual of basaltic or lateritic soils and alluvial gravels in the streams which developed in or near the basaltic terrains.
 
However, due to large number of gem miner is Borai, the local authorities has held concession for allocating the mining areas. The gems mining finally been greatly reduced since 1997. In 2014, the local people have started gem panning near the streams. Today, the area is heavily controlled where the roads at several border checkpoints-heavily guarded.
 
Whilst there is less gem mining these days, Chanthaburi and Bangkok remain international trade centers for ruby. This began with governmental control of the Burmese ruby mines along with an ever-increasing global demand for red ruby, which caused Thailand to become an important source for the red jewel. Subsequently, when large-scale mining in Trat ceased, Thais developed ingenious methods for enhancing cut, color and clarity.