Concha Ostreae
Oyster Shell

Source:
The shell of Ostrea gigas Thunberg. (Fam. Ostreidae).

Distribution:
Mainly from the northern part of Shandong province in China to the northeastern coast of China. Mostly harvested from wild oysters, also from cultivated ones.

Harvest & Processing:
Collect oysters anytime during the year; remove flesh for food; wash shells clean; dry under the sun.

Description:
Elongated and thin, dorsal and ventral brims almost parallel; 10-50 cm long, 4-15 cm thick. Right valve relatively flat, like a lid; scales thick and hard, laminiform (consisting of layers) or forming layered striae; outer surface even or with several depressions, pale purple, greyish-white or dull yellowish-brown in colour; inner surface porcelain-white, with no denticles at either side of umbo. Left valve. Left valve with a deep hollow; scales thicker than those of right valve. The area of the umbo where the two valves are joined together is small. with a deep hollow; scales thicker than those of right valve. Hard; broken surface laminiform, pure white. Odourless; taste: slightly salty.

Indications:
1. Dizziness, tinnitus, irritability and insomnia, convulsion, febrile diseases
2. Subcutaneous nodule, scrofula
3. Emission, enuresis,
4. Menstural disorders
5. Sweating
6. Peptic ulcer

Chemical Composition:
Contains over 90% calcium carbonate (CaCO3).

Note:
According to C.P., also used for medicinal purposes is the shell of O. talienwhanensis Crosse and O. rivularis Gould.