Monday, 15 October 2012

Dear as the wet diver to the eyes 
Of his pale wife, who waits and weeps on shore, 
By sands of Bahrain in the Persian Gulf;
 Plunging all day in the blue waves; at night, 
Having made up his toll of precious pearls,
 Rejoins her in their hut upon the shore.

the words of Sir Edwin Arnold (journalist and poet 1832 -1904) using his poetic license to write a job description of a pearl diver.

I hardly know where to begin so much is written about pearls, from the wonderful imaginative myths of the ancients to the duller pragmatic accounts. I know I prefer to hear that the water that dropped from Venus’ body; as she emerged from the sea, was so affected by her beauty that it formed into Pearls. Slightly more romantic than: When a mollusc is invaded by a parasite or a foreign object that it can't eject, a process known as encystation covers the irritant in successive, concentric layers of nacre; a pearl is eventually formed.

The process of natural pearl formation is so rare that only 1 in 10,000 shells may produce a gem-quality pearl. As the layers of nacre tend to maintain the irregular shape of the original irritant, most natural pearls are irregularly shaped. Natural pearls which are round or spherical in shape are even more rare.

This baroque drop-shaped natural pearl weighing 239.7 grains (59.92 carats) 
 was sold for just under £160,000 at a Christie’s sale.

In the early 20th century demand for pearls led to Japanese scientists developing cultured pearls. By planting a polished bead made from special mussel shell along with a small graft of mantle tissue from a live oyster; the molluscs produce pearls. A typical fresh water mussel can produce up to 16-32 pearls at a time whereas the saltwater oyster can only produce 1 or 2 pearls at a time. Cultivation takes from two to four years depending on conditions, variety and whether it is a fresh or salt water mollusc.
My cultured pearls - I do  have matching earrings -
 I can't remember where I put them though....

Imitation or simulated pearls are entirely manmade. A bead is dipped into a mixture based on crushed fish scales known as "essence d’orient". This coats a bead and produces an imitation pearl. Other lower quality imitations may be made from plastic or ceramics. These are used for costume jewellery and provide an inexpensive way of imitating cultured pearls.

In my next blog, identifying "real" pearls, looking after pearls and more about mother of pearl.

If you really do want to read in detail about pearls take a look at this wonderful book written in 1908 The Book of the Pearl (available to read online).

Wednesday, 10 October 2012

She sells sea shells continued

Looking through my jewellery I found I had other items that had originally been part of or produced by a living organism in the sea - a pendant made from abalone, coral earrings and a pearl necklace.  
my abalone pendant
My pendant made from abalone.
An abalone
Abalone is a common name for any of a group of small to very large edible sea snails. Sizes vary from 20mm to 200mm (or even more). The flesh of an abalone is considered a delicacy and can be consumed raw or cooked. If you are curious, here is how to prepare your abalone for consumption 

The inner layer of an abalone shell.
I am more interested in the the colourful highly iridescent thick inner layer of the shell, known as nacre or mother of pearl. This is produced in layers to protect the soft flesh of the snail being damaged by parasites or debris. The offending body gets trapped in the layers and can form a blister pearl that is attached to the shell or a free pearl ( see below).

This beautiful shell has long been used in jewellery as well as in other decorative items.
Abalone nacre used to emulate the
iridescence of a dragon flies wings

The very skilled use of abalone nacre used
as a decorative infill on this chinese table.

Abalone rarely produce pearls when they do, due to their internal structure, the pearls are often unusual shapes. The most common shape resembling a horn or sharks tooth. Abalone pearls can be very large - over 120mm in length. The value of an abalone pearl is determined by colour, lustre, shape, weight and size. These pearls are so rare that it takes an estimated 100,000 abalone harvested to produce one.

Over-fishing and poaching have reduced wild populations to such an extent that farmed abalone now supplies most of the abalone meat consumed. 
Scientists have found a way to recreate artificial nacre, this has its uses in technology read more here.

Abalone was revered among the native American Navajo, as one of the Navajo's four sacred stones; abalone plays a significant role in many of their myths.

Monday, 8 October 2012

She sells sea shells on the sea shore, part 1

Sanibel Island, USA where the unique angle of the island catches incredible amounts of sea shells on the
sea shore and where I have spent hours obsessively picking up shells to collect with the intention to make "something " from them.
I was wondering, what was the age of oldest jewellery discovered. Thinking it would be made from a metal, I was surprised to see they are beads made from shells. The shells come from a marine mollusc known as Nassarius, which is a type of whelk. Chemical and elemental analysis of sediments stuck to one of the shells showed that it came from ground layers dated to 100,000 years ago, Middle Stone Age. The pea-sized shells all have similar holes which would have allowed them to be strung together into a necklace or bracelet. Researchers believe they were probably selected for their size and deliberately perforated with a sharp flint tool.
The ancient shell beads.

Two of the ancient beads come from Skhul Cave on the slopes of Mount Carmel in Israel. The other comes from the site of Oued Djebbana in Algeria. Where they were discovered was never that close to the sea this means they were transported by people to these locations.
Whether they were worn for decoration, to symbolise status or to ward off evil; we can only speculate.
Here in the Technological Age, 100,000 years later, I have my own necklace made from Nassarius, I wear it purely for decoration although if it does ward off the evil too, thats fine by me.
A testimony of the enduring charm of jewellery - however simple.
My whelk necklace. 
"It is perhaps a more fortunate destiny to have a taste for collecting shells than to be born a millionaire"  Robert Louis Stevenson - 1850

In the past shells were used as money. They were particularly useful because they could be strung in long strips of proportionate value or used to provide a single unit value in  exchange. Relative scarcity of the type of shell used or the way the shell was fashioned determined its value. Cowrie shells were the most common shell money.
Go to this the British Museum page to read more.

Even today there are avid dealers of shells who are are using shells as a way of accumulating wealth. Take a look at this young entrepreneur.