General Gemstone & Diamond Knowledge...

Cut Standards for Fancy Shapes (Non-Rounds)

There are no agreed-upon industry standards for fancy shapes. There are only individual jewelers who provide guidelines, which are based on what they have available to sell you.

The best way to judge the cut of a fancy shape diamond is to look at the stone. If it’s a good cut, it will display brilliance all across the stone face-up; it won’t have dark areas or a see-through effect. Neither will it have a thick girdle (edge) or a deep, bulky pavilion (bottom).

It’s important to learn to judge cut with the eye instead of just with numbers because most of the diamonds you buy will be mounted and won’t come with lab documents and proportion measurements (center stones excepted). You’ll have to look at the stones in semi-mounts, necklaces, bracelets and brooches to determine if they’re well cut. It would make no sense to buy an "ideal-cut" diamond and then place it in a mounting with shallow or deep-cut small diamonds.

Buying Gems Abroad vs. Buying Gems Close to Home

Gems bought overseas aren’t necessarily less expensive than domestic purchases. Nonetheless, they do make great souvenirs and gifts. They’re lightweight and don’t take up much space. They’re usually more appreciated than large, junky gifts. And if you buy gems near the source, you usually have a wider selection and greater range of qualities to choose from than at home. However there are also more opportunities for fraud and misrepresentation.   

Some advantages of buying gems locally are convenience, service, ease of returns and greater recourse against fraud. If you're an astute buyer, you can find deals at home that are just as good as those overseas. 

Before you spend a lot of money on gems abroad, first read the Gem & Jeweler Pocket Guide: A Traveler’s Guide to Buying Diamonds, Colored Gems, Pearls, Gold and Platinum Jeweler. Then make sure the store offers a written 100% money-back guarantee and pay with a credit card that offers consumer protection.

Fluorescence as a Value Factor for Diamonds

If a diamond omits light when stimulated by UV lights or sunlight, it’s fluorescent. Dealers rarely check the fluorescence of a diamond under a UV light to determine if they want to buy it or not. What matters to diamond connoisseurs is the overall brilliance, color, clarity, shape and transparency of the diamond and whether it’s been cut to save weight or enhance brilliance. Nowadays it’s also important to know if the color and clarity are natural or the result of treatments.

Some people are propagating the notion that if a diamond has fluorescence, it’s cloudy. This is false. First of all, practically all diamonds have some degree of fluorescence. Secondly, even diamonds that are strongly fluorescent can be highly transparent, and diamonds with negligible or no fluorescence can be cloudy. The best way to judge transparency is to simply look at the diamond. If it’s cloudy or hazy, don’t buy it unless that’s the effect you’re looking for. Diamonds with the highest clarity and transparency are the most valued.

Diamond buying is already complicated; what’s the point of adding a factor that doesn’t affect the diamond’s beauty?  It is more important to know the 4 C’s (Clarity, Color, Cut and Carat Weight) and how each of these factors plays a role in diamond pricing, which helps you to determine where you would rather spend your money – are carat weight and the type of cut more important to you than color or clarity? Or if money is no object then you can command that all factors be the very best and therefore the comparatively much higher price is worth it to you…

Fluorescence can have a positive effect on some colored gemstones. The world’s most valuable rubies, for example, are noted for having a strong red fluorescence, which helps them have a highly saturated red color throughout.

Insurance Appraisal for Antique Jewelry at a Jewelry Store

It’s best to have antique jewelry appraised by a specialist in antique jewelry.

Antique appraisals must take into consideration that antique jewelry cannot be exactly replaced in today’s market. Therefore, it wouldn’t be appropriate to base the value on the estimated costs to replace the item in newly manufactured condition (which is what jewelry stores usually do).

Value estimations for antique jewelry must be a reflection of the sum to replace the item of similar condition, motif, degree of workmanship, subject to the availability of a like article in the current marketplace. Occasionally an appraisal of antique jewelry is done to authenticate the item. Research for authentication includes provenance, attribution and identification.

Always ask if the appraiser is familiar with the item. A code of ethics states that appraisers shouldn’t accept items they don’t know about.

The Best Way to Clean Gems

One good way of cleaning gemstones is to spray them with a bit of Windex and wipe them with a soft lint-free cloth. The window cleaner evaporates fast without leaving water spots. A cloth moistened with rubbing alcohol is also effective.

Cool water and mild soap is usually safe for all gems. However, gems whose cracks have been masked with oil or other fillers should not be soaked in cleaning solutions because they may remove the fillers. Porous gems such as turquoise, opal, pearls, coral and lapis may also be damaged by cleaning solutions. Just clean them with a soft damp cloth.

Ultrasonic jewelry cleaners can be effective in cleaning very dirty stones, but should be avoided if stones are fragile or have fractures or if there are many smaller prong set diamonds such as a pavé setting.

How to Store Jewelry

A padded jewelry box with lots of compartments is a convenient way to organize your jewelry, but hide it well so burglars won’t find it easily. Keeping a jewelry box in a closet that has a deadbolt type locking door (which makes a good vault substitute) is always a good idea. Cloth pouches and padded jewelry bags with compartments are also good for protecting jewelry and it’s easier to conceal them or place them in safe deposit boxes. Separate jewelry and avoid jumbling it all together because gems and metals can be easily scratched by each other. Nothing can scratch a diamond except another diamond.

1 comment

Very nice!
I am Constance Chaffee and welcome to my website. I saw your post it’s very nice. You have a lot of educational topics on this website and it has taught me a lot and I think it will educate a lot to others. This is a very popular website. Many people will benefit from their education. The first guild of diamond cutters and polishers (Diamantaire) was formed in 1375 in Nuremberg, Germany, and led to the development of various types of “cut”. This has two meanings in relation to diamonds. The first is the shape: square, oval, and so on. The second relates to the specific quality of cut within the shape, and the quality and price will vary greatly based on the cut quality. Since diamonds are one of the hardest materials, special diamond-coated surfaces are used to grind the diamond down.

Constance Chaffee October 14, 2020

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