Edison Pearl
A large bead-nucleated freshwater pearl grown in China, reaching South Sea sizes at freshwater prices.
Edison pearls are freshwater pearls grown around a bead rather than tissue, which lets them reach 10mm to 15mm and stay round.
They come in metallic whites, pinks, purples and golds, often with an unusually sharp lustre.
They are a modern commercial development, named after Thomas Edison, and they have changed what large round pearls cost.
When you are buying
The obvious answer if you want the look of a large South Sea pearl without the price. Ask directly whether a large freshwater pearl is bead-nucleated, since that determines how much nacre is actually there.
Bead Nucleated
Grown around a round shell bead, so the pearl is a nacre shell over a core. The saltwater method, and how roundness is achieved.
Freshwater Pearl
A pearl grown inside a mussel in a river or lake, rather than an oyster in the sea. Most pearl jewellery sold today is freshwater.
South Sea Pearl
The largest commercially grown pearl, from the gold-lipped or silver-lipped oyster. Typically 9mm to 16mm, white to deep gold.
Lustre
How sharply a pearl reflects light. The single most important quality factor, and the one you can judge without any training.