PEARLS

Jodie Diegel, GG, MBA

Graduate GemologistGemological Institute of America

PEARLS The Product

Types of Pearls Farming Cultured Pearls Making Bead Nuclei Nucleating the Oyster Farming Cultured Pearls Raising Production Stock Harvesting Cultures Pearls Processing Cultured Pearls Judging Pearl Value Factors

The Product Pearls are classified by

gemologists as cultured stones. They are not “inorganic” as most

stones are but “organic” They come from an animal or plant Other examples includes amber,

coral, ivory and jet

The Product Natural Pearls Cultured Pearls Saltwater Freshwater

Fewer than 20 species of the 8,000 mollusks produce pearls

The Product The world’s main

pearling grounds were depleted in the 18th century due to constant demand

By the beginning of the twentieth century most of the world’s pearl-producing mollusks were in immediate danger of extinction

The Product Pearls are made of NACRE

A natural substance produced by mollusks that also costs the inside of the animal’s shell (also called “mother of pearl”)

Nacre is made up mostly of calcium carbonate in the form of the mineral aragonite and held together by crystal layers called conchiolin

The Product Natural Pearls

Parasitic Invasion Mollusk forms a sac around the intruder and secretes

nacre from the mantle tissue (the layer of tissue that surrounds the body of the mollusk and lines the shell)

Cultured Pearls Human assistance w/bead or tissue nucleation

Nacre secreted around bead or mantle tissue Beads for saltwater oysters Tissue for freshwater

Fewer than 20 species of the 8,000 mollusks produce pearls (also “keshi” pearls)

The Product Pinctada fucata “Akoya”

Mostly found in Japan White/cream/yellow “Mikimoto” Pearls usually 2-11mm in size,

majority 6-7 mm Usually spherical preferred Approximately 2000 pearl farms in

Japan

The Product Pinctada maxima “South Sea”

Australia, Philippines, Indonesia Largest size yellow/silver Often 9-20 mm with the majority

about 13 mm

The Product Pinctada margaritifera “Tahitian”

French Polynesia (Tahiti) Black/silver Spherical generally range in size from

8-13 mm Often black hue but different tones

Farming Cultured Pearls Natural supply has depleted over

centuries Need highly trained technician and

mantle tissue

Making Bead Nuclei Beads often come from freshwater

shells from US Need minimum sizes to keep

mussels American Pearl Company

Nucleating the Oyster 2 types of nucleation

Bead Tissue

When nucleated: Slow metabolism Careful opening (Tahitian and South

Sea can be re-nucleated) Add Tissue and/or bead nucleus Freshwater usually tissue alone (no

bead)

Farming Cultured Pearls Pearls Farms

Small family farms Large commercial/sophisticated

operations Problems/Challenges

Pollution Severe weather (drought/flooding) Red Tide

Raising Production Stock Collecting from wild

More labor intensive Divers

Hatcheries More controlled but size limited

“Spat” collection Especially Tahitians

Harvesting Cultured Pearls Every 2-3 months mollusks

cleaned Harvesting:

8-24 months Akoya 2 years Tahitian/South Sea 2-6 years Freshwater

Harvesting Cultured Pearls Only South Sea and Tahitian are

kept alive and can be nucleated again Subsequent pearls are LARGER!

Freshwater may be once more Akoya can have up to 5 beads Freshwater can hold up to 50 pieces

of mantle tissue

Processing Cultured Pearls Bleaching Dyes Sorting

Size, shape, luster, surface quality, matching ability

Drilling Full (necklaces) Half (earrings, posts)

Judging Pearl Quality There are 7 features that directly

affect a cultured pearl’s beauty and value

Collectively called “VALUE FACTORS” Understanding these will give you the

product knowledge to help recognize the beauty and rarity of all pearl types

Judging Pearl Quality 1. SIZE A pearl’s ultimate size can depend

on many variables Size and health of the mollusk Size of the nucleus Amount of time in the water adding

layers of nacre Larger pearls usually more valuable

Judging Pearl Quality 2. SHAPE While round is perhaps the most

familiar shape, pearls come in many different forms.

Spherical, Symmetrical, Ovals, buttons, drops, baroque

Judging Pearl Quality 3. COLOR A pearl’s color is made up of Hue-the color’s first impression Tone-its lightness or darkness Saturation-its strength or intensity GIA recognizes 19 pearl hues

Judging Pearl Quality 4. LUSTER “The true magic of a pearl

lies in its luster” and how it reflects light Luster is the most important of all of the

value factors to the beauty of a pearl. 4 categories:

Excellent-reflections bright, sharp, distinct Good-bright reflections but not sharp Fair-weak and hazy Poor-dim, no reflections

Judging Pearl Quality 5. SURFACE QUALITY Cultured pearls are organic so it isn’t

surprising when they show surface characteristics.

Abrasions, bump, chips, cracks, gaps, pit, scratches, spots or wrinkles

Categories: Clean Lightly blemished Moderately blemished Heavily blemished

Judging Pearl Quality 6. NACRE QUALITY Nacre is the very essence of the pearl

itself A pearl’s appearance helps determine its

quality and it has a LOT to do with whether the nacre is thick or thin (thin=“blinking”)

Classifications: Acceptable Nucleus Visible Chalky Appearance

Judging Pearl Quality 7. MATCHING The matching value factor is

relative (only applies to strands, or jewelry with more than one pearl)

Classifications: Excellent Good Fair

CONCLUSION Pearls have been and are forever

fashionable, and were revered in Asia since approx. 4000BC

With the advent of culturing, new and exciting pearls have become available in the last century

More affordable due to great influx of freshwater pearls

CONCLUSION Pearls invoke

words such as

Purity Devotion Love Rarity Romance Elegance

CONCLUSION QUESTIONS?