Gemstone Buying Guide: The 5 C’s

Gemstones have been desired, praised and treasured throughout the history of mankind. They are found in ruins dating back several centuries ago. Gemstones and gemstone jewelry are valued as gifts, often symbolizing love and appreciation.
First point we need to understand is that gemstones are graded by their exclusivity. For example, a 100-carat stone is far rarer than a 1-carat stone and that feature adds to its overall value. However, simply a larger size does not mean that the gemstone is better. Ultimately, it’s the buyers’ preference when determining if the true value of the gemstone is right for them.
As you read the following descriptions, let us clarify, the term ‘grade’ or ‘grading’ refers to the exclusive characteristic of the stone. They do not necessarily mean more durable, (with the single exception of diamonds) more beautiful or better suited for you. When selecting a gemstone, look for the one(s) that makes you feel the best.

Standard Industry Gemstone Grading

If you have read our diamond buying guide, you are familiar with the 4 C's (color, cut, clarity and carat weight). These industry famous 4 C’s apply to colored gemstones as well. However, it’s important that we mentioned a 5th C. Since colored stones provide more variance than diamonds, we need to consider ‘cost’. In other words, what is the true value of the gemstone.

Gemstone Color

The International Colored Gems Association breaks up the color factor into three major components: Hue, (red, green, blue and etc.), saturation, (strong or pastel, deep or shallow and etc.) and tone (too light, light, medium, dark or too dark). The highest value is given to gemstones with purer hues and stronger rich colors. With high-quality stones, subtle variations can make a significant difference in price. For example, a slightly greenish sapphire will not be worth nearly as much as one that is pure blue or bluish purple.
Gemstone Colors
Most people cannot see this difference, but an expert, who observes these gemstones daily, notices the slightest detail. Strong, bold colors are preferred by people with strong personalities; others prefer softer and brighter stones. The color of your skin complexion and outfit has a significant effect on your decision. As you look at gemstones, you’ll notice that only a few of them have the absolute deepest and richest colors. Since these are the most desired, they have premium pricing.
In precise grading terms: Clear, medium-tone, intense and saturated primary colors are the highest in demand. Muted colors and colors between hues, which you may find very attractive, are a more economical option. In the end, the gemstone of your choice is based on personal preference.

Gemstone Clarity

After color, clarity is the next most important factor. Colored stones are almost never as clean as diamonds, and cannot be compared apples to apples. In reality, there is no standardized grading system for clarity and variations will occur for every gemstone. The famous saying, “No two gemstones will ever by the same” applies more to colored stones. With colored gemstones, if an inclusion is not showing on the face up table, than the value goes up. Important stones like emeralds, rubies and sapphires are rarely flawless, but the inclusions may not be noticeable to the naked eye.
Gemstone Clarity
Gemstones are not all the same; some are clean and some are close to heavily included. Gemstones that are nearly flawless are amethyst, aquamarine, blue topaz, citrine, kunzite, tanzanite and yellow beryl. Gemstones that have a few inclusions are ruby, sapphire, spinel and tourmaline. Gemstones that are closer to heavily included are emeralds and red beryl. As a general rule, the less inclusions (or the more clarity), the more the value goes up. In rare cases, the inclusions actually increase a stone's value. The best star sapphires and star rubies are usually translucent and their stemming inclusions, reflecting against the light, produce the star results.

Gemstone Cut

The cut is what gives a gemstone its optimal beauty and brilliance. An ideal cut, which captures all light in an even pattern, without any darkness or windowing, is considered the best.
Gemstone Cuts
A good cut may not cost more, but can add to or deter from beauty. Colored gemstones come in many different cut variations, far more than diamonds. There are no fixed rules about cutting and the ultimate value when it comes to faceting. A skilled cutter makes careful consideration of yield and proportion. Ideally, gemstones should be cut the least while minimizing the amount of inclusions displayed. For these reasons, the cutter first envisions the optimal shape.
Remember, the intensity of color is an important consideration for cutters. Nearly all gemstones become lighter (or shallower) as the carat size is reduced. The color of too dark stones improves as their size is reduced (resulting in a medium color), while light stones become even lighter and begin to lose their value. To be sure, let’s clarify between shape and cut. Shape refers to the physical form or contour of the stone. On the other hand, cut determines how well the shape is executed.

Gemstone Carat Weight

A carat is a metric unit of weight used in the gemstone industry to describe how much a gemstone weighs. A carat is equal to 1/5th of a gram (5 carat equals 1 gram). Thus when referring to decimal fractions of a carat, a point is equal to .01 (1/100th) of a carat.
Gemstone Carat Weight
Larger stones are rarer and per-carat prices will be higher. Relationships between per-carat prices and sizes vary with each gemstone group. Carat weights do not determine the dimensions. The density of a gemstone varies from very light stones like opal to very heavy stones like zircon.

Gemstone Cost

Like any other commodity, supply and demand determine the price of gemstones. Finer gemstones are hardly available in larger quantities and demand remains higher as multiple buyers are searching for the most exclusive (often times the largest) stones.
Gemstone Cost
Deposits are quickly depleting and mining can come to a stop. At other times, mining becomes too expensive when gemstone deposits near the surface are exhausted. Deeper mining processes are more expensive since they require more machinery, fuel, time and effort to recover the gemstones. As the depth increases, the gemstone become more expensive, and when the price of production exceeds the market price, the mining can stop.
Just like demand or fashion, supply may be unpredictable at times, even forming a cycle. Celebrities wearing sapphire, ruby, emerald or tanzanite jewelry at red carpet events increase popularity and demand of those gemstones.

Gemstone Treatments and Enhancements

In the gemstone industry, most gemstones will undergo treatment. Records as far back as 23-79 AD document such processes. Most prevalent is the heat treatment, which enhances the appearance of a gemstone. That is why gemstones are often described as “enhanced”. Treatments nowadays are of a permanent nature, providing maximum color and brilliance. Untreated gemstones are available, but especially in top condition, are found in limited quantities.
Interestingly, in some precious and semi-precious colored gemstones, there are no variations when valuing treated and untreated material. In fact, treating may even increase a gemstone’s value. However, high-quality unheated rubies and sapphires are extremely rare and have a more premium market price. When purchasing high-quality rubies and sapphires, please be advised that unheated material is nearly unheard of, making them astronomically priced. However, for the general population, heat treatment is accepted and praised upon because of their gemstone results.

Common Gemstone Treatments

  • Emerald - Commonly oiled with colorless oil to improve appearance.
  • Ruby - Commonly heated to improve color and appearance.
  • Sapphire - Commonly heated to produce intense or light color and/or improve overall color uniformity.
  • Tanzanite - Commonly heated to produce blue to violet spectrum colors.
  • Aquamarine - Commonly heated to improve color.
  • Blue topaz - Commonly irradiated and heated to produce blue color.
  • Tourmaline - Commonly irradiated to intensify pink, red and purple color.
  • Jade - Commonly impregnated with colorless wax.
  • Lapis lazuli - Commonly impregnated with colorless wax or oil.
  • Coral - Commonly bleached.
  • Pearls - Commonly bleached to improve color and appearance.
  • Black onyx – Almost always dyed.

Lab Created Gemstones

Gemologists use the term “natural gemstones” for stones formed in the earth. Whenever a man-made process is used to simulate the natural conditions and create an identical product, the gemstone is referred to as “lab created”. Just as cultured pearls are a rare nowadays, synthetic, or lab created gemstones are becoming more common. In keeping with up with FTC guidelines, believes in making our customers aware when a particular gemstone is lab created. As appealing as their natural counterparts, labs created gemstones are the best alternative for consumers with budget constraints because of their lack of durability.

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Author : Ankit Daga