Common loose gemstone shapes include round brilliant, oval, emerald (rectangular), square, and marquise (navette), and pear shape.  Other shapes such as the heart shape, opposed bar, and the sphere, and the cabochon are commonly used in jewelry.  Spherical gemstones, of course, are usually formed into beads for stringing or inclusion in wire wrapped jewelry while cabochons, which feature smooth cut facetless surfaces, are ideal for setting in metals like silver.

The process of cutting and polishing gemstones is called gem cutting or lapidary.  All gems are cut by progressive abrasion using finer and finer grits of harder substances.  Diamond bits are uses to cut and polish a wide variety of gemstone types.  Sawing, grinding, sanding, lapping, polishing, drilling, and tumbling are some of the common techniques involved in creating the beautiful gemstones cuts that most are familiar with today.  Some modern jewelers making gemstone art use a combination of faceting and hand carving to create unique gemstone shapes.

Many jewelers choose to buy wholesale loose cut gemstones instead of cutting the pieces themselves, in order to allow them to focus more on the overall piece, than on the complex process of gemstone cutting.  Buying wholesale gemstones can also help to ensure that gems look professional and uniform within a piece.

Without a universal rating system, wholesale buyers found it difficult to judge value and price when comparing competing cz wholesale offers. Without a standardized rating system, there was also no guarantee that cubic zirconia or cz gems purchased from different suppliers would exhibit the same properties, potentially impacting the quality of the end product. As one of the nation’s major wholesale dealers in loose cubic zirconia and loose lab created gems since 1961, PehnecGems recognized the difficulties that lack of an industry rating system posed for both wholesale buyers and sellers.

In an effort to differentiate between and standardize its own cz product offerings, PehnecGems developed the following rating system:

• A – Good quality cubic zirconia preferred by artists and crafters for its beauty at an extremely affordable price. Price makes A-rated cz a cost-effective choice for volume-produced art, crafts, clothing and accessories.
• AAA – Better quality cz with more facets and polish than A-rated stones but fewer facets and less polish than AAAAA-rated cz gems.
• AAAAA - Superior quality cubic zirconia with the most facets and highest polish. Virtually indistinguishable from the highest quality diamonds, AAAAA cz are prized by jewelers and jewelry buyers looking for stunning, high quality, yet affordable jewelry.

The wholesale market responded so positively to PehnecGem’s cz rating system that it has been adopted by many other wholesalers and now provides a reliable guide to wholesale cubic zirconia and cz gem buyers. 

For dependable quality you can trust in wholesale loose cubic zirconia and lab created gems, visit the PehnecGems website at www.pehnec.com. PehnecGems guarantees your complete satisfaction and offers a 100% guarantee on all products.

Viable cubic zirconia was created in the lab in 1930. Interestingly, in 1937 naturally occurring microscopic grains of cz were discovered in metamict zircon by German mineralogists M.V. Stackelberg and K. Chudoba who believed cz to be a product of the metamictization process. Metamictization is the naturally occurring destruction of a mineral’s crystal structure through internal bombardment by radioactive impurities.

Cubic zirconia was first produced for economic use in lasers and other technical optical applications. Because of its extremely high melting point, production was problematic until the perfection of the cold crucible technique by Soviet scientists in the 1970s. Commercial production of cz took off in 1976 and improvements have continued. Loose cubic zirconia are now available in a wide variety of quality and colors from cz wholesalers.

Besides its affordable price, key features that distinguish cubic zirconia from diamonds include:

• CZ is 1.6 times denser and therefore heavier than diamond with a higher specific gravity, 5.6 to 6.0.
• Harder than most natural gems and nearly as hard as diamond’s 10, cz registers 8 on the Mohs scale.
• With a refractive index of 2.17, cz is nearly as refractive as diamond which has an index of 2.42.
• Both cz and diamond exhibit subadamantine luster.
• CZ has an exceptionally high dispersion, 0.060, compared to diamond at 0.044, producing greater prismatic fire.
• Completely colorless AAAAA cubic zirconia, comparable to a perfect D on the diamond color grading scale, can be created in the lab whereas most diamonds contain yellow or brown flaws.

Weight and the fact that cubic zirconia is a thermal insulator while diamond is a thermal conductor are the two easiest ways to distinguish cz from diamonds. On looks alone, the two appear identical.

Gemologists evaluate gemstones using the 4Cs: color, clarity, cut and carat weight. Developed by the Gemological Institute of America (GIA) in the 1940s and 1950s, the 4Cs standardized the evaluation of diamonds and other gems worldwide. Along with development of GIA’s International Diamond Grading System, the 4Cs allowed gem suppliers to make consistent, objective gem comparisons — and customers finally had a reliable way to judge value and price. Developed to grade diamonds, the 4Cs can be applied to any gemstone. 

• Color in diamonds is about what you don’t see. Colorless diamonds have the greatest value. As hints of yellow or brown increase, diamond value decreases.
• Cut refers to the overall shape of the diamond as well as the number, size, shape and plane of the facets that create a diamond’s brilliance and sparkle. The standard round brilliant is the most used shape in diamond jewelry, but fancy shapes such as the marquise, emerald, pear and oval are also popular.  
• Clarity is the absence of marring blemishes or inclusions. Ranging from obvious, visible imperfections to the extremely rare, flawless diamond, most natural gems contain microscopic imperfections caused during their formation.
• Carat weight is the standard metric unit used to weigh gems. One carat equals 0.2 grams, the weight of a paperclip. Carats are divided into 100 points, allowing for precise measurement to the hundred-thousandths of a carat. 

In nature, each diamond and gem is uniquely formed, creating differences in the 4Cs that greatly affect value and potential use. However, in the laboratory diamonds, rubies, sapphires, emeralds and other precious gems can be created that possess the identical chemical composition and exquisite physical characteristics of the most perfect naturally-occurring gemstones. These cz diamonds (cubic zirconia diamonds) and lab created gems ensure that you receive perfect color, cut and clarity in the size required every time you order. For more information on lab created gems and to order, please visit the PehnecGems website at www.pehnec.com.