PEARLS by wulinqing

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Jodie Diegel, GG, MBA
        Graduate Gemologist
   Gemological Institute of America
   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
       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
                 The Product
   Pinctada margaritifera “Tahitian”
       French Polynesia (Tahiti)
       Black/silver
       Spherical generally range in size from 8-13
       Often black hue but different tones
      Farming Cultured Pearls
   Natural supply has depleted over
   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
   Cultured pearls are organic so it isn’t
    surprising when they show surface
   Abrasions, bump, chips, cracks, gaps, pit,
    scratches, spots or wrinkles
   Categories:
       Clean
       Lightly blemished
       Moderately blemished
       Heavily blemished
          Judging Pearl 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
   The matching value factor is relative
    (only applies to strands, or jewelry with
    more than one pearl)
   Classifications:
       Excellent
       Good
       Fair
   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
   Pearls invoke words
    such as

       Purity
       Devotion
       Love
       Rarity
       Romance
       Elegance

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