Following is some information that you should know before shopping for fine jewelry.


The 4 Cs

Some Common  Misleading Terms

Handcraft or Cast

Which  Metal

Other  Considerations

The 4 C’s

Diamond salespeople are always talking about the 4 Cs. This system, with a few changes in definitions, can also be used to grade colored gemstones.


In diamonds, hints of color devalue the stone until the color becomes saturated enough for it to be a fancy colored diamond. With colored gemstones, generally speaking, the deeper the color the more valuable the stone. Stones that change color or have more than one color are more valued than stones that do not. Some colors are more sought after and/or harder to find (often both) which can cause higher prices. Examples are cornflower blue sapphire or chrome green beryl (Emerald). The exception to this is when the color becomes so dark that the brilliance of the stone is lost. This is most often seen in blue sapphires that are black except in strong sun (or store) lighting. One thing to keep in mind is how you plan to wear the piece. Dark stones may not show much color or brilliance in dim light situations.

Diamond color scale
The color scale for diamonds

Colors up to G-H are considered good color. J-K diamonds are considered commercial grade.

Cut:                                                                                                         Back to Top

It could be argued that the cutting is the most important factor in the brilliance of a gemstone. As shown below, a poorly cut stone does not reflect light back through the table of the stone and thus no ‘sparkle’ or brilliance.

There are many different shapes and styles of cuts. Generally you are looking for clean crisp facets with a mirror finish. Points should meet. Sets of facets should be the same size. The table facet should be centered. The culet should be centered. Does the stone appear symmetrical. Is the girdle polished? Does the stone appear symmetrical.

gemstone details
The proportions of the stone are critical and vary from one gem to another. When properly cut, light will reflect from one facet to another and out through the crown in a play of brilliance. If the stone is cut to shallow it will ‘window out’. This means that instead of getting a reflection from the pavillion facets, you will be able to see through them and see whatever is beneath the stone. If the cut is too deep then there will be little or no brilliance or ‘life’ in the stone.


Clarity refers to the flaws or inclusions in the stone. These can consist of tubes, small crystals of other minerals, bubbles (sometimes liquid filled and sometimes with a moving air bubble inside the bubble), and cracks or veils in the stone. It the flaw comes to the surface of the stone, it will interrupt the mirror finish. It also may collect dirt or oils. Oiling and Opticontm (think epoxy) are two methods used to hide flaws that come to the surface.

The diamond industry has a long list of measures of clarity. F=flawless-This means that no flaws can be seen under 10x magnification. (Note: This term is misleading as you can always find flaws at higher magnifications. A truly flawless stone is a fantasy.)

Following is the GIA (Gemological Institute of America) clarity scale for Diamonds:


No blemishes or inclusions when viewed under 10x magnification.

IF=Internally Flawless

No inclusions and only insignificant surface blemishes under 10x magnification.

VVS1-VVS2=Very, very slight inclusions

Minute inclusions that are difficult to see under 10x magnification.

VS1-VS2=Very slight inclusions

Minor inclusions going from difficult to somewhat easy to see, face up, under 10x magnification.

SI1-SI2=Slight inclusions

Noticeable inclusions that are easy to very easy to see under 10x magnification. Eye clean, face up, to the naked eye.

I1, I2, & I3=Imperfect

Obvious inclusions that are usually visible, face up, to the naked eye. Distinctions are based on durability, transparency and brilliance.

Carat Weight:

Most gemstones are sold by weight. There are 5 carats in a gram. Points refer to 100ths of a carat. 50 points=1/2 carat.

Common Misleading Terms

  • Jade: There are two different minerals that are know as jade. Jadeite Jade is also know a Precious or Imperial Jade and Nephrite Jade. Nephrite is the most common jade available. Indian jade is actually adventurine.
  • Topaz: There are instances of smoky or citrine quartz being advertised as ‘Smoky Topaz’ or ‘Golden Topaz’. Be sure that it is indeed Topaz.
  • Diamond: When you hear diamond prefixed by a trade name, ie. ‘Whoever Diamonds’, it is often an attempt to make cubic zirconia sound impressive. They sparkle nice, but don’t think they’re real or expensive. The ‘Ideal Cut Diamond’ is an exception and refers to the cutting. The next big thing for diamonds will be coming up with new and fancier cuts as is already the case for colored gems. I’m sure the people who come up with the new diamond cuts will try to name the new diamond cut, even though it is only new to the diamond industry.
  • Swiss Lapis: Swiss lapis is not lapis lazuli, but a dyed form of jasper. Lapis Lazuli is often dyed.
  • Pink or Red Emerald: Emerald is, by definition, a particular variety of beryl containing certain elements that give it a green color. This so called ‘Pink Emerald’ is actually Morganite, a pink variety of beryl. Trying to call it emerald is just a marketing ploy to try to make it more sellable. The same is true for red, since emeralds are, by definition, green.
  • Ruby Spinel: Ruby is red corundum. Spinel is a completely different mineral. Spinel is a lovely gemstone that comes in several lovely colors, but it is not a ruby.
  • Mt. St. Helen Emerald: This is not Emerald. It isn’t even beryl. This is a manmade stone, which is produced from the ash of the volcano. What it really is, is manmade green obsidian (glass).

Handcrafted or Cast

Handmade items are generally one of a kind, although several similar items could be produced. The jewelry is often designed and executed by the same person. Complex handcrafted items may be more expensive than cast items. There may be more weight in the metal and the labor intense process of designing and building an item cannot be spread out over 20 or 100 or 10000 pieces as can be accomplished with cast jewelry. Handcrafted pieces that are not too labor intensive can be produced at or near the same price as the comparable cast piece. Since there are many levels pf proficiency in the processes of handcrafting jewelry, or anything else for that matter, care must be taken to be sure that the quality you expect is within the capabilities of the artist/craftsman.

Casting is the number one method for the mass production of jewelry. This method involves the construction of a model. This can be done in metal using the same techniques as for handcrafting, the artist can carve the piece in wax and cast the model from that or an organic form, such as a leaf or small pinecone or whatever, may be used. Another method is to make a mold from another piece of jewelry and creating copies. This is being done with some estate jewelry. Cast jewelry is generally less expensive than handcrafted. The construction of the jewelry is greatly simplified as the casting and finishing processes, although involved, are rather easy to master. The art and craftsmanship are most often devoted to the creation of the original model and not to the individual pieces. Setting the stones is the most difficult part of the production process for cast jewelry.

Which Metal

Gold and silver are too soft to be used for most jewelry in their pure state. They are alloyed with other metals to make them harder. Sterling silver is 0925 silver or 92.5% silver. The other .075 or 7.5% is usually copper. For gold the karat number is the number of parts gold out of a possible 24 parts. See the table below for the percntage of gold for some common karats used in jewelry. There are several metals used to alloy with gold to make it harder and to create different colors. Copper, zinc, nickel, palladium and silver are some of the most common alloys. In some countries, the law does not allow the hallmarking (quality stamping) of any gold less than 18 kt. In some countries the laws are so slack or uninforced as to make hallmarking meaningless.

While it is true that 10 kt gold is harder than 14 or 18 kt gold, the difference is not substantial and may be offset by stress fracturing, a problem in some lower karat golds.

Platinum is an excellent metal for jewelry. Unfortunately it is also much more expensive. This is due to several factors. Platinum is usually higher in price  per troy ounce than gold, platinum is much more dense than gold and therefore weighs considerably more than the same piece in gold and platinum is more difficult and time consuming to work with. On the plus side, platinum is a beautiful  white metal that wears extremely well. If you are setting an expensive diamond in a white setting, platinum should be the metal of choice.

10 kt


14 kt


18 kt


20 kt


22 kt


  • Plated, filled, rolled and electroplated are all methods of layering a precious metal over a less precious metal. Silver over brass or copper, gold over silver, etc.
  • Prongs made of platinum will last much longer than prongs made of gold or silver, although platinum is substantially more expensive than gold. If the gemstone is expensive, however, the cost of the setting will be minor. It is generally not wise to mount a $10,000.00 diamond in a $50.00 setting.

Other Considerations

Over time gold or silver will wear down. This can happen over months or years depending on how you wear your  jewelry and how well the jewelry is constructed. If the stone is set high, the prongs should have a little more substance as they will receive more wear than usual. A little extra metal in the prongs is very seldom a bad thing. Rings wear on top and bottom. Rings with stones that are worn constantly will usually require that the band be replaced someday. The  thinner the band the sooner this will happen. Earrings do not receive much wear. Most damage to quality earrings occurs in the jewelry box.

What is the durability of the stone(s) in the piece?                                            Back to Top

    Hardness and toughness are two different things when considering the wearablity of a particular gemstone.  Hardness is a measure of the materials resistance to scratching. Toughness is a measure of the stones resistance to  chipping or breaking. Almost any stone, including diamonds, can be chipped if struck against a hard surface. The following is a chart for some common gemstones. The higher the number the harder. This is not a proportional scale. For instance a diamond is 140 times harder than a sapphire.



Can only be scratch by another diamond.



Very durable. Will show wear after years of wear.

Spinel & Topaz


Still quite hard. These gemstones hold up well.

& Garnet


Wears pretty well. If worn everyday it will show wear with time. Shouldn’t be worn while gardening or around abrasives.



Same as above



Stones that are softer than quartz (7) are subject to wear from everyday dust and sand which can contain fine particles of quartz. Cabochons, ie. opal or jade, wear better than faceted stones.









Very soft. Will scratch easily. Some components of makeup can wear on these.

    Toughness is a measure of how well the stone can withstand being struck. Diamond and Topaz have excellent hardness, but due to the fact that they cleave easily in certain directions, they are more easily chipped than sapphire for instance which has excellent toughness, but is less than 1/100th the hardness of Diamond. Jade (both  nephrite and jadeite) is very tough though they will scratch more easily. Gems such as Opal and Tanzanite should be shown special care. They are not very hard or tough. If you wear your rings while gardening you would do well to stay away from these gem materials.

 Has the gemstone(s) been treated?                                                               Back to Top

    A treatment is anything that is done to the gemstone to improve its color or clarity and thus its value. When buying from a designer/craftsman, the stones may have been cut by the same person. In this case all treatments should be  known and disclosed if any exist. If the stone was purchased from a wholesaler, then the treatments, if any, may not be known. The following shows some common treatments.


Often oiled or waxed.

Ruby/Sapphire/Tanzanite/ Aquamarine

Often heat treated (Tanzanite always heat treated).

Blue Topaz

Almost always heat treated and irradiated.

Smokey Quartz

Sometimes irradiated.

Jade, Chalcedony, Diamond & many others.


 What kind of Jade is it?                                                                                  Back to Top

    There are two minerals that are sold as jade. Nephrite and Jadeite. Nephrite jade is a variety of actinolite and has a hardness of 5-6. Jadeite has a hardness of 6.5-7. Jadeite is also known as ‘Precious Jade’.

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