Gemstones

Pearls

I admittedly knew little about pearls prior to venturing into jewelry in 2022.  I knew there were natural pearls, and manufactured by man versions.  Within the natural pearl realm, I knew freshwater and cultured.  And that your front teeth are a good place to test the roughness / smoothness to distinguish the natural from manufactured.  I could deduce the difference by weight, and perhaps "feel", and have an uneducated guess as to what a strand was made from, but I wouldn't know you could tell the difference by how cool they felt and how that would change with extended contact.  

What propelled me to write this section at this time (30th October, 2022) is a sterling pendant and earrings set that features Lake Biwa pearls and gemstones.  The Biwa pearls are "blister pearls", and each has a blister of a red-brown color, with the familiar "pearlescence" creamy pink flat next to it such as "mother of pearl".  

As with my M.O. (modus operandae) at the start of Lumigrate in 2008/9, where the palate of experts I had for videos I'd offer for download or DVD purchase held "doctorate degrees" -- medical, naturopathy, acupuncture and oriental medicine (at the time, the only one in Colorado!), psychology (two of those, one specializing in neurology and pain, the other in performance and the mind/brain - body connection), my goal with education about jewelry is to do the work for the consumer and sort through available informants to provide my audience with what I think is relevant, competent, and most helpful.  

The granddaddy in the professional jewelry industry is Gemological Institue of America, or GIA. Search results at the GIA website on "Biwa blister pearl" yeilded over 1,000 results!  I'll provide a bit more about them, below, when wrapping it up on this portion of information.

The era a piece is made that utilized pearl came into play in investigating what I might describe the set I will be providing for someone to purchase. This is done online using resale platforms as well as niche websites for "vintage", or more specifically as in this case, the decade or period of creation, such as  "mid century". 

For my purposes today, I preferred what I found at this link at "Gemstones dot com": Blister Pearl Gem Guide and Properties Chart | Gemstones.com

Blister pearls are large pearls that have intergrown with mollusks or freshwater mussels and are integrated with the shell. Solid “blister” pearls are akin to mabé pearls, but they are natural and not assembled. They are known to have a high luster and are more durable than mabé pearls. They are typically rounded or irregular in shape and have been known reach 2 cm in size.

They are more often found in in larger Pinctadas molluscs. They are called “puku” in the Cook Islands. They are also found in freshwater river mussels in North America. The freshwater blisters pearls are often found in mussels with distorted shells and are come in irregular, round or button shapes. Snail blisters are created when small snails or mollusks invade the mussel shell. Blisters pearls have also been found in “Lion’s Paw Pearls” in Laguna Ojo de Liebre in Baja California, Mexico, and Conch pearls in the Caribbean.

In a nutshell (or oyster shell, in this case), what I'd gathered from learning around the Interweb prior to arriving at GIA's site or Gemstones.com is this: the Japanese Lake Biwa was the starting point for freshwater pearls, back in the late 1800s and throughout much of the 20th century.  Much like "kleenex", in my mind, "Biwa" was the word people adopted for freshwater pearls, which lasted well past mid-century.  

As others in the world wanted to get in on the freshwater pearl market, things changed, and it was a good thing, because Lake Biwa increasingly became polluted and today produces very little.  So little, in fact, one source I read said it couldn't produce anymore at all.  

At the GIA site, there's a topic about a producer that began creating blister pearls that fit the description of the ones in the pieces I'm looking into, with the orange-red-brown influenced blister next to mother-of-pearl smooth such as in the earrings.  Or, in the case of the pearl in the pendant, the colored blister is neighboring two more immature, I'd imagine, blisters which have the color at the end further from the predominant feature of the pearl feature in the rounded rectangular sterling setting. 

BUT that occurred in the 1990s, and these vintage pieces are recognized as from the 1980s (from similars online).  In 1980's, is it probable the blister pearls in these pieces I'm looking into could be from Lake Biwa?  Yes!  And since at that time the lingo hadn't generalized to call them "freshwater" instead of Biwa, it's also perhaps correct for me to say these are Biwa.  

And indeed, pearl was in it's heyday in the 1980s.  I recall asking for pearls for Christmas in 1986 or 1987.  

From the professional (certified) jeweler that's been mentoring me and leading me into this jewelry world, I've learned that turquise has a simlar issue.  At the booth at the Gem and Mineral show in our valley, I sat nearby and overheard a lot of the questions people asked, and learned a lot.  The answer about where turquise comes from based on it's appearance was: "unless you were there and saw it mined, you'll not really know -- nor be able to say -- the location".   

To complicate the matter, another site I liked tweeked things a bit, saying you call them Mabé pearl once out of the oyster / shell, but in it's initial form, primitively, it's called blister pearl.  (timeless pearl dot com)

Also called blister pearls or half-pearls, Mabe pearls are grown against the inside of the oyster’s shell, rather than within its tissue. These pearls typically have a hemispherical shape with a flat back. While the pearl is still in the oyster, it is called a blister pearl. After reworking, it is referred to as a Mabe pearl.

Small blister pearls are commonly found in nature, and therefore not very expensive, except when they are produced by certain rare mollusk species. Mabe pearls are beautiful, making them attractive in jewelry. They come in a wide range of vibrant and exotic colors, ranging from light pink to bluish shades with hues that gleam rainbow-like. Pink Mabe pearls with golden swirls are extremely rare.

Arriving at Pearl-Guide.com, however, I felt like I'd met a "peer" in a way, as it's clearly an older website, from the era before even Lumigrate, though their search bar still functions.  Since my "first thought" when seeing the set I'm researching and taking you along for the fun in learning was it was abilone, I selected this topic and found a really good overview!  

VI. Common Mabe Pearl Varieties - Abalone Mabe | Pearl Education - Pearl-Guide.com

I'll leave off here about "blister", Mabe, Biwa, trusting this is enough to get you reSearching more if it's piqued your interest. 

From GIA, navigating to their About thread, this is their succinct overview:

A Tradition of Science and Education

Established in 1931, GIA is the world's foremost authority on diamonds, colored stones, and pearls.  A public benefit, nonprofit institute, GIA is the leading source of knowledge, standards, and education in gems and jewelry.  

 Here's the link to GIA / Gemological Institute of America: Gemological Institute Of America | All About Gemstones - GIA