Grading The Quality of Gemstones

Grading The Quality of Gemstones

Among of the 21 birth stones spread over 12 months, diamonds are the hardest and most popular gems. De Beers is the diamond company that invented modern advertising and consumer psychological testing. We have been thoroughly indoctrinated with the notion that diamonds are the most valuable things on the planet. They are associated with love, eternity and marriage.

Substi­tutes of varying degrees of quality are avail­able. Cubic Zirconia (CZ) is com­monly thought to be the only imita­tion. But CZ, or zircon, comes in several grades, and you can purchase both less more expen­sive alterna­tives to CZ. Various attributes determine the value and ideal use of diamond alternatives.

Birthstones
Common birthstones for January: garnet, February: amethyst, March: aquamarine; April: diamond; May: emerald; June: pearl; July: ruby; August: peridot; September: sapphire; October: opal; November: topaz; December: tanzanite.

Hardness is defined as a material’s resistance to perma­nent indenta­tion (scratches) on the Mohs scale, developed by German mineralogist Friedrich Mohs in 1812. Generally speaking, 7 or higher on the Mohs scale usually indicates a gem is hard enough for normal jewelry use, but there are exceptions.

Wearability can be excellent, very good, good, poor, or display only. Most gem­stones would be considered “brittle,” as measured by tenacity (resistance to blows). Though a diamond is the hardest gem known to man, it is paradoxically brittle. Hence, its setting often includes prongs around the circumference for protection. Quartz is less hard than diamond but can take considerable blows without damage.

Gemstone Production Hardness
Diamond Natural 10
HPHT Diamond Cultured 10
Moissanite Synthetic 9.25
Carbon Coated CZ Synthetic 9.1
White Sapphire Synthetic 9
Cubic Zirconia Synthetic 8.5
Quartz Natural 7
Glass Synthetic 5.5
Plastic Synthetic 2

Cultured diamonds are identical to natural diamonds with the exception of a laser-imprinted serial number. They increase availa­bility of rarer natural diamonds at slightly lower cost. They also open the opportunity for chocolate, or tinted diamonds.

Grading The Quality of Gemstones

Synthetic moissanite has the exact same properties of very rare natural moissanite (discovered in 1893 by Henri Moissan). With more disco-light fire than diamonds, moissanite is nearly as hard. In the late 1980s the synthesis of moissanite and loose moissanite stone was finally achieved. In 1997, Charles & Colvard® began to market synthetic moissanite jewelry and moissanite loose stones. An average one-carat diamond costs about $1500 dollars, whereas a one-carat moissanite loose stone may cost around $300 dollars and up, depending on the cut—an 80 percent savings.

Cubic Zirconia stones are rated from A to AAAAA. A is the Lowest Quality, while AAAAA is the highest grade CZ available. The rating system is based on several variables, the same Four Cs used to determine the quality of diamonds: Cut, Clarity, Color and Carat.

A Grade CZ Stones—Lowest quality grades of Cubic Zirconia are used by craftsmen and artists for embellishing their creations.

AAA Grade CZ Stones—More highly polished than A-grade stones with better luster and shine, used to create reasona­bly priced jewelry.

AAAAA Grade CZ Stones—Crafted by the best stone cutters and polished just like any top rated diamond would be. They can resemble diamonds but are not as durable, eventually losing sparkle, so are not recommended for rings worn every day.

Most people do not spend thousands of dollars for each piece of jewelry. They may have a few nice items augmented by lesser quality costume jewelry. This minimizes financial liability in the event of loss while providing a wider range of gems to wear year round.

ClinicalPins include low-cost gems designed to wear to work. Most are alloy metals. Also available are stainless steel, sterling silver, silver and gold plating. The stone of choice for most pins is AAA or AAAAA grade CZ.

References
  1. Why we’re wired to covet jewels. bostonglobe.com
  2. Man Made Diamonds And Comparing Simulant, Synthetic Rings. everything-wedding-rings.com
  3. How Does Moissanite Compare to Diamond? everything-wedding-rings.com
  4. Gemstone Hardness and Wearability. gemsociety.org
  5. Mohs Hardness Scale. geology.com
  6. Mohs scale of mineral hardness. wikipedia.org
  7. Hardness Of Plastics And Rubbers. polymerdatabase.com
  8. What is Cubic Zirconia? and The Properties of CZ. everything-wedding-rings.com
  9. Cubic Zirconia Grading. jewelry-secrets.com

May 08, 2019 by Kevin Williams

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