Sea Shell Black pearl necklace

Necklace of 47cm composed of black pearls of 10mm of diameter.
The pearls underwent a treatment which gave them this color aubergine.
These pearls are perfectly round and the collar was entirely tied. Culture of the fresh water pearls exist since the Fifties in the north of KYOTO (Japan) in lake BIWA (jap: biwaco). Into fresh water oysters (Hyriopsis schlegeli), one introduces only square pieces of epithelium of 4mm, most of the time without core. The exceptional size of these molluscs (20x11cm) makes it possible to make there up to ten insertions in each half with sometimes another moreover comprising one mother-of-pearl core. Each operation gives rise to a pearl-bearing bag and its pearl. At the end of one year the pearls have 6 with 8mm diameter and are seldom round. They are withdrawn from oysters and are reintroduced to improve the form of it.