The Pearl Guide
Pearl Valuation Factors
Pearls are categorized and sorted based on eight quality and valuation factors: size, shape, color, nacre, luster, orient, surface and coherence.
Size
Most pearls are measured by their diameter; though, irregularly shaped baroque pearls are measured by their width and occasionally, length. The standard unit of measure is the millimeter.
From 1 millimeter to over 20 millimeters, the size of a cultured pearl depends on several factors. These factors include the size of the parent mollusk, the size of the implanted nucleus and the length of cultivation. All other factors equal: the larger the pearl, the greater its value.
Orient
The play of light refracted through many layers of concentric nacre creates orient, the iridescence of a pearl that sometimes creates a rainbow effect. The Latin word oriens means ‘the rising of the sun.’
Surface
‘Cleanliness’ affects the value of a pearl. Generally, the fewer blemishes on the pearl, the better. Tiny irregularities are acceptable and can be a test of authenticity.
Coherence
Each pearl is unique. In order to create jewelry, pearls that complement or match each other are selected in a process that may take years. Thousands of pearls may be rejected to find the desired combination. When results are successful, the piece works as a harmonious whole — it has coherence, balance.
Shape
Pearls Come In An Infinite Variety Of Shapes, Partially Determined By The Shape Of The Nucleus Around Which The Pearl Is Formed. No Matter The Shape, A Pearl Falls Into One Of Four Main Categories:
-
Round
Symmetrical spheres
-
Semi-Round
Spherical oval, pear-shape and teardrop
-
Baroque
Irregular
-
Circled
Streaks, ridges or rings in regular formation on the upper third (min.) of the pearl’s surface.
Color
From opaline white to anthracite black, the palest pastels to vibrant hues, pearls come in almost every color and shade. The finest pearls have a subtle interplay of colors – the primary body color plus delicate overtones.
Nacre
Nacre is the crystalline substance that pearls and its parent mollusk are made from – layer by layer nacre builds up around the small bead or piece of shell (the nucleus) that is implanted during the culturing process. The thicker the nacre, the more lustrous and durable the pearl.
Luster
Pearls have a rich, inner glow that seems to come from deep within — that’s luster! Luster is an effect caused by light reflecting and diffusing through layers of nacre; high luster tends to make a pearl more valuable.