Tuesday, June 9, 2015

Birthstones: Pearl (June)

What do pearls and kidney stones have in common? They're both organic minerals!

And the similarity stops and ends there. Sorry. that wasn't really a great joke. But imagine, for a second, if there were a race of aliens who thought our kidney stones were gorgeous and cultivated us for the express purpose of harvesting them. Gah!

June is one of a myriad of "alternative" birthstones for June. The original Tiffany & Co. poems used agate, but the Kansas City 1912 list instead has pearl and moonstone. The updated Kansas City list added alexandrite. So, theoretically, June has 4 (!!) birthstones. I've already talked about agates and alexandrite. Today, we're moving on to pearls.

Like opal, pearl is not a true mineral. (Opal, as you'll recall, is a mineraloid: an "almost" mineral.) An organic mineral, as you've probably already guessed, is one formed by a living, biological creature. The two most common examples of organic minerals are pearls and the aforementioned kidney stones.

Pearls are made up of two parts: small bits of calcium carbonate (CaCO3) held together with conchiolon, the proteins a mollusk's mantle secretes to protect itself. Together, this milky-white material is called nacre, or mother-of-pearl.

Pearls have a long history in human culture. They could be found wherever there were mollusks, basically, and their milky, iridescent luster captured anyone and everyone's attention.
  • Krishna is said to have discovered the first one and given it to his daughter on her wedding day. In Vedic astrology, pearls are associated with the moon, water and water-related things, and the sign Cancer. They're also thought to ensure good sleep.
  • Egyptians were decorating items with mother-of-pearl as far back as 4000 BCE. After the Persian invasion, pearls themselves also became fashionable and valuable (though never as valuable as gold).
  • Rome went mad for them around 100 BCE: women sewed them into couches and on the hems of their gowns. Paradise, according to the Koran, is absolutely dripping with pearls.
  • By 230 BCE, the Chinese had pearl experts who looked down their noses at "strings of pearls not quite round," and by 500 CE they were creating their own nacre-shellacked images by placing lead figures on shells:


Chinese origin, currently on display in the museum on Mikimoto Pearl Island in Japan.

The English name "pearl" comes from the French perle, which in turn is derived from the Latin perna ("leg"), the name given to the leg-shaped bivalve whence pearls derive.

Pearls remained a rarity and a luxury (literal tons of bivalves have to be harvested to find just a handful of gem-quality pearls) until pearl farming appeared in the beginning of the 20th century. What at first glance looks like a couple of dates is actually a fascinating, if often overlooked, story!

Mikimoto is the name associated with cultured pearls in the business today. Because people were slow to take to cultured pearls, Mikimoto went balls-out in terms of promotion. At one point he publicly burned "inferior" pearls, just to drive home the message that the cultured pearls from Mikimoto Company were of a superior quality! Such antics made him a legend (at least in some circles), and so the process was attributed solely to him.

However, this is probably not the whole story.

The outstanding cultured pearl patents of the time were granted to Mikimoto...and the unlikely combination of a government biologist (Tokishi Nishikawa) and a carpenter (Tatsuhei Mise). Nishikawa and Mise had, by 1907, received a patent for their pearl-growing method. Mikimoto appears to have continued his own studies for some time (receiving a patent on a technique in 1916), but his methods couldn't mach the Nishikawa–Mise process in terms of efficiency and commercial viability. He eventually came to some kind of arrangement with the pair—whether the marriage of Mikimoto's daughter to Nishikawa was a love match or part of the arrangement, I can't find—and thus began the boom for Mikimoto Company.

This is all stuff that can be confirmed by looking at the paperwork. So far, so good.

But where did the Nishikawa–Mise method come from?

Most likely from a British marine biologist named William Saville-Kent, but there doesn't seem to be much of a paper trail to confirm it. Saville-Kent never took out any patents on pearl farming, possibly because it was one of a myriad of marine biologic interests for him, and possibly because he died in 1908. Mikimoto, on the other hand, had been obsessed with pearls from a young age and had little to no education to speak of. Pearls were his game: it was that or nothing. He had at least three patents to his name, all about cultured pearls. He also outlived Saville-Kent by quite a few years, not dying until 1954.

Nishikawa and Mise themselves are little more than nobodies who only appear as footnotes in pearl history (and in their 1907 patent).

Here is the most likely trail from Saville-Kent to Mikimoto:

Nishikawa was sent to Thursday Island, Australia in 1901 with the Arafura Pearling Fleet, where he eventually met Mise's stepfather (Mise and Nishikawa would not meet until they both returned to Japan). Saville-Kent was there at the same time with the official title of "Fisheries Commissioner."

Beyond that, it is unclear when or if paths ever crossed. Nishikawa and Mise could have met Saville-Kent, or they could have just met some of his collaborators and coworkers. At some point they must have at least heard of Saville-Kent's work in some detail, as the Nishikawa–Mise method in no way resembles the old Chinese lead figure method, but it's impossible to tell if they outright copied Saville-Kent's method or were merely inspired by it.

As a reward for reading all that, check out the world's largest pearl: the Pearl of Allah (sometimes called the Pearl of Lao Tze), clocking in at 14 pounds:

Courtesy Drow male; it's 9 inches across and originated in the Philippines

Note the lack of luster: this is not a nacreous pearl, formed by a mussel or an oyster. It is, instead, much more akin to man-made porcelain and comes from a giant goddamn clam. Technically clam pearls are pearls, but they are usually only of interest to rock hounds and collectors, not jewelers. Remember, clams can get pretty huge.

Like, this huge (and more). Courtesy Mike Baird.

There are further distinctions: freshwater pearls (from freshwater mussels that can be cultivated all over the world) and saltwater pearls (from saltwater pearl oysters that require warm waters to survive). "Freshwater" is often another trade name for "cultured" (that is, farmed) pearls, but wild freshwater pearls are possible (just rare).

Imitation pearls are also popular and made from a wide variety of material: plastic, glass, alabaster, or crushed mussel shell. An easy way to tell if your pearl is imitation or not is to rub it on your teeth (fingernails work too, if you're in a store or in public); real pearls, regardless of cultured or not, will feel gritty, while imitation pearls will feel smooth. To determine if a pearl is wild or cultured, a gemologist has to X-ray the stone to see what lies beneath the nacreous surface.


There's a whole lot more to pearls that I didn't have room to go into here. For a thorough and academic look at pearls and pearl farming, you can find The Pearl Oyster on Amazon or GoogleBooks. I also used Antoinette L. Matlin's The Pearl Book (also available on Amazon). 



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