Chemistry:Dragon Bone Stone

Dragon Bone Stone (龍紋石), is Taiwan’s (台灣) local special mineral. Dragon Bone Stone’s color is mainly bronze due to the rich copper minerals it contains, which are oxidized over the time.

Taiwan is one of the pacific islands located on the Pacific Volcano Zone. In its history, the island had frequent geothermal and volcano activities. Geothermal activity causes Taiwan’s subterranean strata to jostle one another under conditions of extreme high pressure and heat. Many famous gem mines were born in this way. For example, Taiwan’s Hualien county (花蓮) produces high quality and quantity marble (大理石) and opal (貓眼石).

When geothermal activity turns into orogeny (the formation of mountains), the mine is pushed out from the subterranean stratum and raised high up together. The gem mine is now located in the high altitude mountains in Taiwan’s Central Mountain Range (中央山脈).

The distinctive appearance of Dragon Bone Stone is due the metal, jade, and stone contained within it. When its stone part is polished, it can appear black, olive green, crimson red, orange colors. When its metal part is polished, it reveals titanium silver and golden bronze colors. When its jade part is polished, it shows green jade, milk white, amber colors. After polishing the metal part, the metal shows different lines and images similar to shiny metal bones or scales implants perfectly together with jade and stone. It is called Dragon Bone Stone because of the presence of these scales.

Dragon Bone Stone’s hardness is softer than quartz (hardness 7.0). It has hardness 5.5 ~ 6. Human finger nails are about 2.5.

Dragon Bone Stone can be found on the riverbeds of Zhuo-Shui Xi (also known as: Cho-Shui Xi, literally means River of Turbidity, 濁水溪) and Laui-Lon Xi (Mustard Thick River, 荖濃溪). Most of the stones are carried down by the river current from the high mountains. In year 1999, Taiwan experienced grievous “921 Earthquake”. The source of Dragon Bone Stone mine was broken and cut off. It became more difficult to obtain the stones.

Taiwan does not mass-produce Dragon Bone Stone due to its scarcity. In any case, the stones are also difficult to find. The miners look up and search stones one by one on the riverbed. Sometimes, even a whole day's search does not reveal a single stone. Moreover, after the 921 earthquake broke the mine vein, fewer stones flushed down together with river current.

There are only two ways to increase the quantity. One way is for a miner to adventure into high mountains to find the original source of the gem. It may take few days to several weeks, and sometimes a search is in vain. The other way is to go into dangerous river beds when the water level is high, immediately after the typhoons have died. Typhoons bring a tremendous amount of rain. In these conditions, river turbulence produces enough force to carry and flush down more new stones to the riverbeds. However, the miners must risk their lives to gather the stones at the risk of mountain river torrent. Therefore, a Dragon Bone Stone is expensive.

Dragon Bone Stone can weigh from grams to tons. The huge ones are usually placed at hotel lobbies as collectables after being polished. The small ones are good for necklaces and accessories after being professionally jewelry designed. The stone itself gives owners classic, elegant and noble decorations.

The most popular small Dragon Bone Stones are rounded. These are easily polished and lend themselves to making simple yet beautiful jewellery.