Jeweller - April 2022
Diamond disruption: How the Russia-Ukraine conflict is changing global trade High time for change: Where to for watch brands after Baselworld? Darkness & light: Uncover the mysteries of black and white gemstones
Diamond disruption: How the Russia-Ukraine conflict is changing global trade
High time for change: Where to for watch brands after Baselworld?
Darkness & light: Uncover the mysteries of black and white gemstones
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Pearls Part I: Freshwater<br />
Above: Pacharee; Blue Nile; Mizuki<br />
Below: GIA; Mizuki<br />
Pearls – an organic gem - have been<br />
revered pieces of treasure for thousands<br />
of years, having adorned the necks of<br />
nobility spanning across Persia, Babylon,<br />
Egypt, Rome, and beyond.<br />
Before cultured pearls became<br />
commercially available at the beginning of<br />
the 20th century, all pearl jewellery featured<br />
natural pearls formed from wild molluscs.<br />
Top quality pearls were highly expensive<br />
and mostly reserved for royalty and the<br />
exorbitantly wealthy.<br />
When an irritant enters a pearl-producing<br />
mollusc, the mollusc enlists a defence<br />
mechanism in which it coats the irritant<br />
in thousands of microscopic layers of its<br />
nacre, which become the pearl.<br />
Cultured pearls are pearls that have grown<br />
over a bead nucleus or tissue irritant that<br />
humans have intentionally placed into<br />
the mollusc. This can be done in various<br />
species of mollusc, in both marine and<br />
freshwater environments.<br />
Natural freshwater pearls are currently<br />
very rare, with most known localities now<br />
protected by law.<br />
Throughout history, natural freshwater<br />
pearls have been found in most countries<br />
all over the world, though the United<br />
States was once one of the larger<br />
producers. Scotland is another important<br />
historical source.<br />
The GIA and other institutions are<br />
currently developing techniques for the<br />
DNA barcoding of freshwater pearls, to<br />
understand them better and identify them.<br />
The culturing of freshwater pearls initially<br />
began in Lake Biwa, Japan during the<br />
1920s. It was in the freshwater mussel<br />
Hyriopsis schlegeli at Lake Biwa where<br />
the successful cultivation of pearls with<br />
mantle tissue alone (instead of a bead<br />
nucleus) was achieved.<br />
A combination of pollution issues and an<br />
improvement in quality of pearls coming<br />
from China saw the collapse of the oncebooming<br />
production at Lake Biwa. Today,<br />
cultured freshwater pearls are largely<br />
grown in ponds, lakes, and rivers in China.<br />
Compared with other pearl varieties,<br />
freshwater pearls have a particularly large<br />
range of sizes, from as little as
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