Oyster (Oblong shell, curved, rough layered texture, milky white and gray spots inside the shell, smooth and glossy, dense layered texture on the hard cross-section)

Calcined Oyster

Mountain Oyster

Calcined Mountain Oyster

【Naming】

Oyster

【Source】

Superior Grade of the Materia Medica

【Frequency of Use】

B

【Botanical Origin】

Shells of the oyster family, Ostrea gigas Thunb., Ostrea talienwhanensis Crosse, Ostrea rivularis Gould, or related animals.

【Characteristics】

Irregular oval, triangular, or oblong shell, varying in size, usually 10-30 cm long, 5-10 cm wide, and 1-3 cm thick; outer surface is gray, light grayish-brown, or grayish-blue, layered, with curved, rough layers. The inner surface of the shell is mostly milky white, smooth and glossy, with horizontal lines at the base, no luster, and wavy layers at the edges. The left shell is thicker and larger than the right shell, uneven, and the outer surface of the shell is often attached with sea snails, moss, etc., and there are often holes on the surface, with small shells inside the holes; the right shell is thinner and smaller, and flatter. Hard in texture, not easy to break, white and layered cross-section. Odorless, slightly salty taste.
Ostrea gigas is elongated, up to 35cm long, scales are strong and thick layered, hard in texture, cross-section is layered and white, taste is slightly salty. Ostrea rivularis is mostly rounded or oval, scales are concentric and layered on top of each other. Ostrea talienwhanensis is triangular, scales are slightly firm and wavy. Easy to distinguish.

【Processing】

1. Raw Oyster 2. Calcined Oyster

【Identification】

“It is best to collect them in November” – *Annotations to the Materia Medica*.
“Illustrated Materia Medica states: It is a type of shellfish found in the sea, and the male ones are better”, “Generally, the larger ones are considered better”. – *Classified Materia Medica*.
“Oysters that face left are better” – *Essentials of Benevolent Arts*.
“The shells that have been aged for a long time are better” – *Yakucho*.
Good quality oysters are large, intact, free of impurities, soil, and breakage, and have a glossy interior.

【Category】

Invertebrates