Welcome to Twin Diamonds ! Sign In or Register

Home | Wish List | Order Status | Shopping Cart | Help| עברית

Live Help            866-215-3174
Search Twin-Diamonds
Free world wide shipping30 days return policy 40,000 Loose Diamonds All credit cards and PayPal

Buying a Gemstone

Welcome to Twin-Diamonds Gemological Education Center and Guidance to Gemstones, Diamonds & Jewelry

 

Back To Main Menu Back To Twin-Diamonds Web Site
 

Buying Emerald

When judging an Emerald 's value, its color is of paramount importance.
The more vivid the green, the more valuable the stone.
There are also attractive lighter green Emerald that are lively and vivid when set in Emerald Jewelry and darker green gems that make up in rich green color what they lose in brightness. Generally speaking, however, very light or dark Emerald are less expensive.
Unlike a Diamond Diamond, a finely colored Emerald is not significantly devalued by inclusions. The fewer fissures, the more expensive the Emerald . Cut natural Emerald of top quality weighing more than two carats are extremely rare and costly.
A large deep green Emerald with minor blue or yellow secondary coloration that is relatively free of inclusions may cost tens of thousands per dollars per carat. Perfect natural gems in color and appearance are very rare and expensive.
As part of the normal fashioning process, most Emerald are immersed in clear oil or resin to minimize the appearance of small fissures.
In addition to oil and wax fillers, the trade also uses clear resins to penetrate open fissures surfacing in the gemstone.
Hardeners are often added to solidify these liquids to prevent the resin from evaporating, thus making the enhancement more permanent than just oiling or waxing the gem.
Be sure to buy from a reputable dealer who will provide, in writing, the processes and treatment that your Emerald has received. Because Emerald are brittle, and can split along their inclusions if exposed to sharp impact, properly designed Emerald jewelry should minimize the gem's exposure, especially in rings and bracelets.




Jump To Top Back To Twin-Diamonds Web Site
 

Buying Ruby Rubies

Color is of paramount importance when judging the value of a Ruby . Prized colors which can command high prices are pure reds with no overtones of brown or blue. Very light or dark shades are usually less valuable, but not necessarily less appealing. Beauty is in the eye of the beholder and color preferences are subjective.

Of course, clarity, cut and carat weight factor into the cost of a gem.
Better quality Ruby Rubies are usually eye-clean with some inclusions under magnification. Ruby is more available under two carats, gems over five carats have become scarce. In Ruby 's finest quality, any size is rare.

Don't let yourself become overly concerned about the origin of the gem.
A gem from Burma may not necessarily be better than a gem from Vietnam.
If the Ruby has a color that appeals to you, and a clarity that looks good, then that is more important than its nationality. However, it is important to buy from a reputable dealer who will provide written documentation about the Ruby 's size, and any treatments it has undergone.

Recently, Ruby Rubies have been grown in the laboratory. Although these grown rubies are essentially of identical composition, hardness, and brilliance to natural Ruby Rubies, they have aroused some controversy. Their presence of the market is still more limited than lab-grown emeralds, however.
When buying Ruby Star Rubies, look for a star that has straight legs that are all of equal clarity.




Jump To Top Back To Twin-Diamonds Web Site
 

Buying Sapphires

Color is of paramount importance when judging the value of Sapphire . The purer the blue of a natural Sapphire , the greater the price the gemstone can command. Gems that are too dark or too pale are usually less valuable, but not necessarily less appealing. Beauty is in the eye of the beholder and color preferences are subjective.
In recent years technology has perfected the process of heat-treating sapphires exposing them to very high temperatures to eliminate impurities. In fact most Sapphires on the market today have been heat-treated to improve clarity and color. This process is stable and does not affect the value of the gem, except at the highest level of the market.
Occasionally, colorless to pale blue sapphire is diffusion treated. This process alters the color of a gem by exposing the surface to certain chemicals (the same used by nature). The treatment is fairly stable, but it is confined to the surface of the gem only. This could create a problem, if the Sapphire is ever badly chipped or nicked and needs to be recut or repolished. Diffusion treatment is not the same as heat treatment.
Additionally, some fancy Sapphire is irradiated to produce intense shades of yellow or orange. This process, however, is not very stable. The temporary color produced by this method can quickly fade in light or heat. It is important to buy fine Sapphire from a reputable retailer who will provide, in writing, all pertinent information regarding the gem including enhancements and special care notes.
A gem's clarity and cut also factor into its cost, as well as carat weight. Better quality sapphires are usually eye-clean with some inclusions under magnification. Sapphire is more available in sizes under two carats, but gems of 5 to 10 carats are not unusual. Sapphire reaches a far greater size than Ruby .




Jump To Top Back To Twin-Diamonds Web Site
 

Tips on buying gemstones /h3> Always make a careful, naked-eye observation of the gemstone you intend to buy. Observe the gem in all directions under different lighting conditions (natural light, incandescent, fluorescent, halogen). This first careful observation is the key to establishing the identity, characteristics and quality of the material under analysis. 

Hold the stone in your fingers and feel it. Don't use tweezers or magnifying lenses at this stage. 

Pay close attention to the color of the gemstone. It is normally this first color impression that will indicate the origin of the stone, whether it is natural, and what country it is from or whether synthetics or imitations should be suspected. 

Don't forget that color is the most important factor in the price evaluation of colored gemstones and the most difficult to determine. If you are not proficient in the color subtleties of the stone you are observing, seek the assistance of a qualified gem dealer. 

Carefully study the surface of the gemstone by tilting it and using oblique lighting techniques to view the surface. If cracks and fissures are detected with the naked eye, it is a sign of a highly -treated stone that could be damaged easily. Make sure the gemstone surface is free of grease, dust or anything that might interfere with your observation. 

Carefully observe the brilliance of the stone and the faceting style. These elements will be considered in the identification and price evaluation process. 

Once this initial observation stage is completed and if you have not observed damages that could endanger the stone, proceed to handle the stone with tweezers and a 10X loop. 

Study the stones' transparency and clarity, the second most important aspect in price evaluation. 

Look closely at the features that will confirm the right identity of the gemstone. Pay close attention to the inclusions. This can yield a fair assessment of the mine origin. And, this can affect overall brilliance and durability of the material. 

Continue by studying the surface of the stone, make sure you are not looking perpendicular to the surface, but in an oblique fashion. This technique will allow you to observe the treated areas of the stone starting from the surface where the treating agent was introduced. Alternate between dark and light backfields. This will aid your observation of the internal features and fractures. Try to determine the origin of the enhancing material that will affect the overall presence and durability of the stone in the future. When in doubt, seek the assistance of a qualified gem testing laboratory. 

Observe the overall cutting and polishing of the surfaces. This is the third most important factor in the price assessment of a gemstone. It will affect the brilliance of the gemstone. 

Shape and overall balance and harmony of form are important factors in the marketability of gemstones. Keep this in mind. 

Don't forget the maxim, "It's too good to be true," when presented with a gemstone at a below market price. Be aware, the material is either something different from what it appears to be under naked eye observation or its provenance is doubtful. Keep away from both situations. 

Don't forget the most important factor in buying gemstones is to do it whenever possible through well established, reputable dealers or jewelry stores. 

When buying a gemstone, if you do not have experience, request a Gemological Certificate of Identification, issued by a qualified third party not related in any manner to the seller. 

The buying tips given here apply best to loose stones. Gemstones set in jewelry are generally more complex to identify and evaluate, especially if set low on the mountings. 

There are gemologists and qualified laboratories in most major cities in the world. For a partial listing, please refer to the section Gem Labs For further referrals and gemstone information, please refer to the section on Trade Organizations, Education.




Jump To Top Back To Twin-Diamonds Web Site