This is one of those rare shells that produce pearls. This listing is for one single shell, half of the oyster, so you can see both the lustrous iridescent polished exterior and the mother of pearl, nacreous interior.
Pearls form when a small particle enters into the oyster and nacre is released by the oyster to coat the particle or object, eventually creating a small pearl. The particle might be a grain of sand, organic material, or even a parasite. The oyster's release of the nacre serves as an adaptation of the immune system to isolate the invasive particle. This type of shell also in particular produces gray or black pearls.
These typically measure from 10cm by 8cm. Colours and sizes will vary; these are natural shells and the photograph is of a typical example, not the shell you will receive. If you have any particular requests in terms of colour or size, please pop them in the notes - we’ll do our best to find the shell that comes closest to what you want!