Pearl is the tough calcium carbonate substance which is produced from the oyster. The classical pearl is the round and smooth pearl on the contrary it is dense to jewel in the natural. So the reward of the example pearl is very expensive.

There are the 2 above type of pearl source. However they may sometimes contemplate entirely the corresponding and dense to diagram the source.

1. Bite Drool Pearl; The most general pearl source in the world.
2. Freshwater Pearl

Freshwater pearl shell is a benevolent of bipolar oyster, which has barn door shape, thick layer and attraction nacreous layer inside. There are multifold usages of the pearl shell such as house furniture decoration, accessories and bags. Moreover, Pearl shells are used in cosmetic and medicine industries.

In Thailand, the specie of pearl shell; Chamberlainia hainesiana obtain been exported to Japan for breeding industries amassed than 25 years. There are 2 species of pearl shells in Thailand (Kanjanaburi): C. hainesiana and Hyriopsis (Limnoscapha myeriana). In the year of 1994, the specie of C. hainesiana could breed and desert to the connatural for the positive ecology. It endow that both types of pearl shells habit in one shot the river. Sometime you testament examine the freshwater pearl mussels are living in lakes and ponds.

Biology of pearl shell

1. Entity cycle
The enthusiasm cycle of pearl shell is coinciding to other bipolar oyster. There are two sexes of the shells. In the season of breeding, the females will catch the germ from the virile shell to inhalant siphon and store in marsupial. After that it will virile and evolve to glochidia and juvenile and costless living anatomy at the latest cycle.
2. The maturity
The maturity of H. (L.) Myeriana will hold 7.92 centimetres great of shell, 26 grams weight. The maturity of C. hainesiana at the hour of 2 oldness carry 15.12 centimeters lenghty of shell and 390 grams weight.
3. The season of fertility
It was reported that the fertility season enter on from Sept to March. The lifetime from marsupial to for love living cast holding 6 - 10 days up to the sphere temperature. In one year, the shell C. Hainesiana can beget marsupial standard 10.50 times on the other hand H. (L.) myeriana can arrange marsupial morals 18.92 times per year.
4. Host of the pearl shells
Both species of pearl shells in the leaf of glochidia as host and prosper to juvenile. One fish can be host of one glochidia on account of of the limitation of serum glucose of the fish.

The Freshwater Pearl in Thailand

Pearl record of Calcium Carbonate (CaCO3) (aragonite 82 - 86 %), conchiolin 10 - 14 % and inundate 2 - 4 %. The hardness is 3.5 - 4.5 %. The particular gravity is 2.7.
Type of pearl: There are 2 types of pearls

1. Familiar Pearl
The general pearls author from the non-native substance in anticipated contaminate in layer and nacreous layer of the shell.
2. Culture Pearl
The culture pearl causes from the human place some facts into the shell and wait until the suitable size. There are 2 kinds of culture pearls
2.1 Hemispherical pearl or Half pearl
2.2 Spherical pearl
- Non-nucleated pearl; with this development will invest in irregular shape of pearl
- Nucleated pearl; by this process, the supplier will bend cycle pearl, fairness layer and flying value.