Contrary to common belief, a grain of sand is not the cause as the mollusc can easily flush this out of its shell.Larger sharper pieces of floating debris and natural parasites, however, it can't.

Now if it can’t eject the intruder; by pumping water through its shell–equivalent to us shaking our foot – the mollusc decides it has to live with it and starts depositing the substance it uses to build its shell called Nacre (a type of Calcium Carbonate in the form of Aragonite). This builds up in layers around the irritant to eventually form the pearl.

This natural reaction to irritation will occur regardless of whether the mollusc is a Seawater Oyster or Freshwater Mussel.

Natural pearls have been prized for thousands of years as natures ultimate treasure-why?-because they are formed by the serendipity of organic nature-and as such one might compare their creation to the miracle of childbirth – each one unique and beautiful.

Diamonds and all other hard stones however, are formed by the brutal processes of inorganic nature and owe their conception to violent pressure, heat and eventual cooling and crystallisation.

Throughout the ages natural pearls, sometimes called “Orient Pearls”, have been referred to by religious texts and historians. From antiquity until the last century the main oyster beds were found in the Persian Gulf. Countries such as Bahrain and Qatar would sell their pearls to Indian merchants who would drill and thread the pearls in to small hanks (short collections of threaded pearls) known as “Bombay Bunches” for resale to the European trade.

Today, mainly due to pollution and scarcity, the majority of the natural pearls found for sale are “regenerated” pearls that were originally found by divers very many years ago.

In Scotland the River Tay, in the vicinity of the town of Perth, still has a reputation for producing natural freshwater pearls.

It is known that Queen Victoria owned some very fine examples. This gives and indication of the regard in which these gems were held.

Large, round natural Pearls of good quality are so rare that they rank along side the most valuable of all gems.