Pearls are not technically a crystal, as they are created from organic matter, however they are one of the most universally prized of all crystals. The Romans held them in such high regard that anyone of low rank was forbidden from wearing them by law. They were strongly admired by kings - in 1597 Spanish King Phillip II was gifted a pearl that weighed 1250 grains/80 grams (a regular 7.5mm pearl weighs about 0.6 grams!). Pearl fishers from Borneo believed that Pearls had the ability to 'breed', and it was customary for them to place every 9th Pearl they found into a bottle with two grains of rice for every pearl, for these special pearls had the power to reproduce. However they were also supposed to seal these bottles with a dead man's finger!