Pearls are the only gem produced by a living organism.
Coveted and treasured for centuries, find out how these gems are formed and the characteristics that make each unique.
Key Pearl Types
- These wild oysters are found in abundance in an isolated region off Northern Australia
- Pinctada maxima oyster
- Primarily silver lip oysters
- Predominantly produces white, silver, and pink pearls
- No enhancement required for fine quality pearls
- Typically 10-16mm, with rare examples exceeding 20mm
- 1 pearl per oyster every 2-3 years
- Current production is approximately 800,000 pearls per annum
- Wild oysters account for approximately 70% of the production
- Retail value: Approximately US$300 million per annum
These wild oysters are found in Indonesia, Papua New Guinea, The Phillipines, and Vietnam
- Pinctada maxima oyster
- Primarily gold lip oysters
- Typically 8-14mm
- 1 pearl per oyster every 1-2 years
- Oysters are grown in hatcheries
- Current production is approximately 300 million pearls per annum
- Retail value: US$230m per annum
- Tahiti, French Polynesia, Marshall and Cook Islands, Solomon Islands, Fiji
- Colours from black to 'peacock' green and other exotic colours
- Shapes similar to Australian South Sea pearls, including round, drop, circle, button, oval and baroque
- Fine quality pearls larger than 10mm in classic shapes are becoming increasingly scarce
- Typically 8-13mm, with rare examples up to 18mm
- 1 pearl per oyster every 2 years
- Approximately 7.4 million pearls per annum
- 100% of Tahitian black pearls are produced by hatchery-reared oysters
- Retail value: Approximately US$220 million per annum
- Previously produced solely in Japan, but now primarily produced in China from hatchery-reared oysters
- Nacre thickness typically less than 0.1mm
- Predominantly round or near round in shape
- Quality tends to diminish over time
- Typically 5-8mm, with rare examples exceeding 12mm
- Up to five pearls per oyster every 6 to 12 months
- 44 million pearls per annum
- Retail value: US$300 million per annum
- The cultured pearl cycle is approximately 6 months
- Primarily in China
- Produced by freshwater mussels such as Hyriopsis in China and Japan
- Environmental concern
- Most commonly produced in non-classic or “barrel” shapes
- Production generally between 3-15mm
- Up to 100 pearls per mussel
- Approximately 1500 tonnes (or 1 billion pearls) per annum
- Retail value: US$400m per annum
Fine quality natural pearls are extremely rare. In the wild, perhaps only 1 in 10,000 oysters will produce a natural pearl of jewellery quality.
The exact cause that results in the formation of a natural pearl is not fully understood. It was once believed that natural pearls formed in response to a foreign substance (for example, a piece of grit) making its way into the shell of the oyster. Initially it was believed that the oyster coated the invader in layers of nacre as a 'defence mechanism' to protect itself from the substance. While this may be the case in rare examples, research in recent years suggests that natural pearls may actually occur more spontaneously and inexplicably - further adding to their mystique.
To produce pearls of natural beauty with no enhancement requires farming practices that mimic the natural life of the oyster as closely as possible. For more than 50 years, Australian pearl farmers have sought to understand the secret behind the Pinctada maxima’s ability to produce natural pearls of superlative quality.
Pearls with natural colour and lustre
As with all gemstones, fine quality pearls that require no enhancement are exceedingly rare and highly prized, and this is reflected in their value.Learn more about Australian South Sea pearls
Pearls with enhanced colour and lustre
As with other gemstones, the processing of pearls is a common practice that makes attractive jewellery accessible to a wider market.
Processes such as light chemical treatments may improve the appearance of a lower quality pearl. The improved lustre resulting from light processing may fade after a few years, but this does not damage the pearl's structure. Heavy chemical treatments may adversely affect the physical integrity of a pearl and can sometimes impart a coarse and chalky look and feel.