Colored Gemstone Beads

Do you use colored gemstone beads in your jewelry? Have you ever wondered what the gemstone bead ratings actually mean? Do you know the difference between an A graded gemstone bead and one with a B or C rating? Why are some beads classed as AAA or A+?

Look no further! Over the last four weeks we have been discussing the criteria on which fine high-end colored gemstones are assessed, and this week we turn our attention to beads and explore the characteristics of the different grades of colored gemstone beads.

Beads From left: B Grade Natural Peridot, C Grade Dyed & Heated Carnelian, A Grade Natural Lapis Lazuli

The first thing to say is that - as with cut colored gemstones - there is no universally acknowledged system for grading colored gemstone beads. Occasionally suppliers will use the same systems as for assessing the cut stones (see last week's article). However most use a scale of grades from A to C, where an A rated bead is the highest quality, and C is lowest.

Some suppliers such as The Curious Gem will generally only sell high quality A rated gemstone beads, so they use codes like AA and AAA to indicate relative quality within a grade. Other suppliers may use + or - to describe the relative superiority of beads within a particular grade. Yet other suppliers, such as Fire Mountain Gems, allocate grades from A through F to their colored gemstone beads, although E and F are rarely used.

Beads From left: C Grade Heated Citrine, B Grade Natural Aventurine, B Grade Heated Tanzanite

Pricing

Because of the varying standards it can be really difficult to compare like with like, but as always price is a very good indicator of quality. When comparing bead prices between suppliers, the most important things to look for are the same as with cut colored gemstones - Three Cs - that is the color, the clarity and the cut of the beads.

Don't forget that the rarity of the gemstones themselves, and the skill of the cutter, both play a significant role in determining the price. High quality, expertly cut beads with good color and clarity are much more desirable - and will always be more expensive - than lower quality beads. All things being equal, carat weight will play a part in the price, so larger beads with the same rating will cost more than smaller ones.

Beads From left: A Grade Enhanced TurquoiseA Grade Natural MalachiteB Grade Heated Yellow Sapphire

Of course, there is a world of difference between the one-off, painstakingly hand-cut specimen gemstones we looked at last week, and the plethora of strands of colored gemstone beads we're talking about here. But then, there is a huge difference in price too! Jewelry designers will want to bear in mind that it's extremely unusual for the very best quality gemstones to be cut into beads, because they can fetch much higher prices as faceted gems destined for setting in fine jewelry. Yet while A graded colored gemstone beads may not be the same fabulous quality as priceless cut gemstones, they can still look gorgeous in your designs!

Machine Cut versus Hand Cut?

Machine cut gemstone beads will have more precise and uniform facets, and should be well polished and well drilled. Because of this they will be more sparkly and brilliant, and their color will appear to be better. By contrast, many gemstone beads are hand cut, with far fewer facets, and by their very nature they will not be absolutely uniform in shape and size. Their color is unlikely to be as radiant as machine cut beads, and they will not display as much brilliance. Similarly, the size and position of drill holes may vary.

Beads From left: B Grade Heated Sapphire, B Grade Oiled Emerald, C Grade Dyed Ruby

The following is a very general guideline to the grades applied to colored gemstone beads:

A Grade

A is usually the highest grade, given to high quality beads that are suitable for use in a wide range of very good quality jewelry designs. Depending on the gemstone, light inclusions may be present, but generally speaking a strand of A rated gemstone beads should display very good color and clarity, be very well cut and evenly drilled, and be uniform in color, shape and size. If you see an AA or A+ grade, this may mean that the color, clarity or cut is even better than usual, while AAA graded colored gemstone beads should be eye clean and as close to perfect as you can get.

B Grade

B rated gemstone beads should still be of good quality, and suitable for use in many jewelry designs, especially stringing applications. However, their color, clarity and cut will not be as good as A rated beads, and their lower price will reflect this. All the beads in a strand are likely to vary from one another in color, shape and size, and internal and external flaws will be visible. It is advisable to factor in a certain amount of wastage, as you may find the quality is such that you cannot use all of the beads, or they make break or ship when you attempt to string them.

C to F Grades

These are the lowest rating colored gemstone beads, and because they are much less desirable than the higher grades they will have the lowest price tag. They will have very obvious flaws, inclusions and surface imperfections, and are likely to be very variable in shape and size. Beads in this category will probably be poorly drilled, or drilled off center, and may be brittle. But depending on what you want to use them for, they may still be a good value purchase - just check the beads very carefully before buying and make sure that they are suitable for your intended jewelry project.

Beads From left: B Grade Irradiated Blue Topaz, A Grade Natural Labradorite, A Grade Natural Fluorite

Suppliers

It is important to choose your supplier carefully, and only buy from reputable and, ideally, qualified sources. Beware of internet sellers who describing their gemstone beads as AAA, AAA+, or AAAA as their claims may be subjective and not based on genuine assessment, and certificated gemstone dealers do not as a rule apply grades in this way. If in doubt, before reaching for your wallet, ask the supplier to show you their GIA (or equivalent) certificate of assessment for the beads.

Real or Fake?

If you're buying on the internet, don't be fooled into thinking you are getting a bargain, when you may be being ripped off! There are minimum manufacturing costs associated with the production of all gemstones, and you really do get what you pay for. And beware of fakes: in a random search on Etsy I spotted a strand of "AA grade" aquamarine beads on sale for $10. Think about the Three Cs for a moment - unless someone has made a typo, genuine AA quality natural aquamarines are going to be much more expensive than $10 a strand! Having said that, those $10 beads may be exactly what you're looking for - just don't expect them to be top quality gemstones.

Beads From left: B Grade Oiled Emerald, B Grade Natural Tourmaline, C Grade Heated Aquamarine

Gemstone or Glass?

I quite often see glass beads being misleadingly sold as gemstones, especially quartz. It is difficult to tell the two apart without a microscope, but genuine quartz has a very distinctive crystalline structure which is not present in glass. If you have a loupe, check to see if there are any perfectly round air bubbles. If so, it's glass not quartz. Also, a genuine quartz bead is harder than glass and will scratch glass easily. I was once advised to wear an old watch when buying gemstones, so you can run the quartz gently over the glass watch face. If it leaves a scratch mark, the bead is quartz. If not, it's glass. However, I wouldn't recommend doing this without the consent of the supplier - you might end up with more than a scratched watch face!!!!!

Finally, remember that if the price of a gemstone bead seems to good to be true, then it probably is!

Assessing Colored Gemstones, Part 4 - Cut

In this final part of our JET Team discussion about assessing fine colored gemstones, we look at the importance of cut in grading the stones. All gemstone images are courtesy of Heritage Auctions.

Cut refers to the manner in which a stone has been cut - such as emerald-cut, step-cut, brilliant-cut - rather than to its overall shape. The skill of the cutter is demonstrated by the quality of cut, which can have a big impact on the overall color. Thus the way a stone is cut not only determines the final beauty and brilliance of that gemstone, it also affects its grade and value.

From left: Very good oval pink spinel, 5.97ct
Very good enhanced octagonal emerald, 4ct
Good oval blue zircon, 6.32ct

The most important factors here are the proportions and symmetry of the cut, and the way a stone has been polished. The cut should be neither too shallow nor too deep, and there should be a sharp and well-defined difference between the top part, or crown, of the gemstone and the lower part, or pavillion. For the highest grade the facets should be expertly cut and well-proportioned, and should be polished so that the finished gemstone reflects and transmits light evenly, giving it a bright and glittery brilliance.

From left: Very good oval golden beryl, 60.50ct
Excellent octagonal step-cut natural sapphire, 20.21ct
Excellent oval natural yellow-green tourmaline, 4.89ct

With pearls, lustre is what gives them their pearly quality, and is the way they reflect and diffuse light. Thus more lustrous pearls will be graded higher than less lustrous examples. Unlike other colored gemstones, pearls are also graded according to their shape and size. So, for example, round pearls should be as close as possible to perfectly round with the naked eye. Natural, saltwater pearls are valued much more highly than cultured pearls, while freshwater pearls are generally less valuable.

From left: Very good enhanced pear-shaped paraiba tourmaline, 1.24 ctExcellent oval-shaped pink sapphire, 2.54ctVery good natural saltwater conch pearl, 6.40ct

We hope you've found this discussion helpful! If you're considering purchasing colored gemstones, Gemfields has a useful online Buyer’s Guide.

Assessing Colored Gemstones, Part 3 - Clarity

In this third part of our JET Team discussion about how fine colored gemstones are assessed, we look at how clarity contributes to the overall gemstone grade. All gemstone images shown are courtesy of Heritage Auctions.

Clarity is the second most important factor in grading colored gemstones, and describes any inclusions (flaws) within or blemishes on the surface of a gemstone. The higher grades are usually given to gemstones that are "eye clean", with no flaws visible to the naked eye. However, flawless colored gemstones are very rare indeed, and will therefore command very high prices.

Thus, unlike diamonds, unless the flaws are very large and/or numerous, or likely to affect the durability of the stone, minor inclusions don't usually affect the price of colored gemstones. Indeed, with some gemstones they are regarded as acceptable - these include sapphires, rubies, garnet and peridot. Star sapphires, for example, aren't star sapphire unless they exhibit needle inclusions!

From left: Very good oval kunzite, 17.31ct Very good oval paraiba tourmaline, 4.15ct Fair black opal cabochon, 7.24ct

Other stones, such as emeralds, beryls and tourmaline are very rarely found in nature without inclusions, and a long-established and industry accepted way of improving the clarity of emeralds, for example, is to fill them with oil or resin to make the inclusions less visible.

Because of the clarity differences between different types of gemstones, the untreated stones themselves are usually classified as Type I, Type II or Type III gemstones:

• Type I coloured gemstones usually grow with no inclusions visible to the naked eye, including aquamarine, morganite, tanzanite and blue topaz
• Type II coloured gemstones usually grow with some minor inclusions visible to the naked eye, including garnet, peridot, ruby and sapphire
• Type III coloured gemstones almost always have inclusions visible to the naked eye, including emerald and tourmaline

From left: Very good pear-shaped citrine, 59.36ctGood round-cut demantoid garnet, 3.67ctVery good oval colour changing alexandrite, 5.36 ct

Opaque gemstones are graded differently again since by their nature they do not transmit light, but they should still reflect light well. they should not have any cracks or fissures, or feature undesirable inclusions. But as always there are exceptions! For example, inclusions such as veining can be acceptable - and sometimes even desirable - in certain types of stone, such as lapis lazuli.

Assessing Colored Gemstones, Part 2 - Colour

In this second part of our JET Team discussion about assessing fine colored gemstones, we look at the most important factor in grading the stones, color. All gemstone images are courtesy of Heritage Auctions.

Color is without doubt the most important factor in grading all colored gemstones. Of key importance is whether the colour is natural, or has been achieved through treating the stone in some way - untreated, richly colored gemstones are generally worth far more than those that have been enhanced by being heat treated or dyed. The gemstone industry has accepted methods of enhancing certain stones - for example amethysts, aquamarines, sapphires, citrines, rubies and tanzanite may be heat treated, while blue topaz is often irradiated, to improve their color.

From left: Very good emerald-cut smokey quartz, 158ct
Very good oval sapphire cabochon, 7.55ct
Excellent modified-rectangule topaz, 35.95ct

Because different stones have different characteristics, each type of gemstone has its own unique standards for optimal color and clarity. Regardless of the grading scale being used, three factors determine the grading of gemstones for color. These are hue, tone, and saturation:

• Hue is the basic color itself, such as blue or red, and the most valuable colored gemstones will have the purest color. The GIA grading system describes 31 basic colors or hues
• Tone refers to the lightness or darkness of color, such as dark blue or light red. The GIA system has 11 tones describing depth of color, of which medium-light to medium-dark tones are generally the most valuable
• Saturation refers to the purity and intensity of the colour, and often determines how a gemstone will be cut. The GIA system groups colours into cool hues such as blue, and warm hues such as red, each with six degrees of saturation. The most valuable gemstones usually display strong color saturation

From left: Excellent oval natural ruby, 2.09ct
Very good rectangular apatite, 2.38ct
Good oval peridot cabochon, 18.04ct

Assessing Colored Gemstones, Part 1 - The Three Cs

Have you ever wondered how colored gemstones are assessed and graded? This week, the JET Team begins a four-part discussion explaining the basics of assessing fine colored gemstones. We start by taking a look at the criteria on which grading is based. All gemstone images shown are courtesy of Heritage Auctions.

Diamonds are valued and rated with the Four Cs - color, clarity, cut and carat. Colored gemstones are evaluated similarly, but while carat weight will affect the final price of a colored gemstone, the size itself is not graded. Thus colored gemstones are evaluated only on the Three Cs of color, clarity and cut, and the final grade of a colored gemstone will take all three of these factors into account.

Left: Excellent rectangular citrine, 68.60ct
Excellent bluish violet oval tanzanite, 14.95ct
Good emerald-cut tourmaline, 3.38ct

While diamonds are always graded according to the same international criteria, there is unfortunately no universal grading system for colored gemstones. For example, AGL (American Gemological Laboratories), AIGS (Asian Institute of Gemological Sciences) and GIA (Gemological Institute of America) all have their own, different rating systems, and there are many more systems also in use across the globe.

Some suppliers describe colored gemstones using words like Excellent, Fine, Very Good and Good, but each supplier may apply the terms using slightly different criteria. Other suppliers may use comparable terminology of Extra Fine, Fine, Good and Commercial. Potential gemstone buyers need to be aware of these differences, and make sure they know which scale has been used to determine the grade of their colored gemstone.

From left: Excellent emerald-shaped aquamarine, 32.93ct Good cushion-cut yellow sapphire, 26.80ct Excellent oval amethyst, 133.52ct

The following table shows a basic comparison of the most commonly used systems used for grading colored gemstones:

From left: Very good undrilled black South Sea cultured pearl, 14x13.5mmExcellent whistle-cut rhodolite garnet, 5.22ctVery good black opal cabochon, 7.98ct

Attending Bead Shows

Do you love going to gem and bead shows? Members of the JET Team definitely do! You may recall that not long ago Wanda visited the Treasures of the Earth Gem Show, and several of the team got together at the Tucson Gem Show. Today Kerry, aka WanderingJeweler, gives us her tips on how to get the best out of your visit to a bead show...

Choices, choices!

A few weekends ago I attended the Fraser Valley Bead Show in Burnaby, BC, Canada - I took all these photos at that show. I love attending bead shows, but they can be a bit overwhelming with all those shiny beads and tools.

The best parts of attending shows are the demos and classes, and seeing all the latest tools and materials all in one place. Here are some of the tips that I’ve gathered over the years, to help you get the most out of attending bead shows!

Watching a Kumihimo Demonstration

Before You Go:

• Take an inventory of what beads and supplies you have, and then make a list of what you need
• If you need specialty items, or if you are in dire need of a specific bead or supply, it's a good idea to contact some of the vendors beforehand - many of them will be happy to bring the supplies to the show for you
• Wear comfortable clothing and shoes - you’ll probably be spending a lot of time on your feet!
• Check out the vendor list and mark down all the vendors (and their booth numbers, if available) that you don’t want to miss
• Take a notepad so you can make sketches, write down the booth numbers, and make a note of items and prices. My notepad has a useful pocket for business cards

A dazzling display!

When You Get There:

• Resist the temptation to spend all your money at the first booth!
• Take a quick look at all the booths before buying, to scope out the ones with the best quality and prices
• Sometimes you can get discounts if you buy a lot of items from each vendor - don't be afraid to ask vendors for volume discounts
• I also try to go on the last day to get the best prices, but be careful as you might miss out on the trendy items
• Most of all, have fun!

Observing a Soldering Demonstration

If you have some tips you'd like to share on visiting bead shows, please add them in the comments below - we'd love to hear them!
Kerry