Grading of Gemstones

Gemstone grading systems like Cut grade, Carat weight, Density per cubic inch (gem density) are used by gemologists to determine the quality and value of natural gemstones for jewelry making. Gem grading systems are not standardized, so they differ from country to country.

Like other gemstones, the value of citrine gemstones is determined mainly by their rarity. One well-cut citrine can be more valuable than a large number of less desirable stones. For example, the dark-yellow variety of citrine that is transparent and has fine quality is rarer than other citrines, so it tends to command higher prices. The color of a citrine stone can also affect its value. Most citrine jewelry pieces are yellow or orange in color, but a dark-yellow or a brownish-yellow variety of citrine that appears reddish-orange under some light sources can be very valuable if it is transparent. While citrine is generally a relatively inexpensive stone, it is more expensive than many other important jadeite and quartz varieties that do not appear in jewelry. 

The price of citrine was stable or falling when the Thai market collapsed in late 2001, but prices rose slightly again in mid-2002. One reason why prices increased occurred was because a flood-damaged Thai production factories around this time. In 2003, prices of citrine rose by nearly 50% in several months, because of supplies in China. From 1988 to 1999, prices of citrine rose steadily but saw a sharp decline from 2000 to 2003. The high value of citrine jewelry pieces is one factor that drives the demand for the stone. Another reason that causes citrine to be more expensive than other gemstones is that it was believed, before the Thai gemstone industry went into a slump in late 2001, that as many as 90% percent of all jadeite and quartz stones produced were being purchased by the Chinese market and turned into jewelry. The Chinese market collapsed in late 2001, and jewelry producers that do not produce citrine have suffered from the shortage of these stones.

Gem Grading and Quality

Even though we may use the term “quality” when describing the properties of gems, that doesn’t necessarily mean that one gem is better than another. Ultimately, you’ll purchase the gem that’s best for you personally. When a gem receives a high grade for a property, that means it has rare features within that property. What’s best for you may not necessarily be the “top” or rarest grade of the gem.

Natural gemstones for jewelry making deposits will yield pieces with a wide variety of qualities. Let’s say, for example, someone just mined 100 pounds of amethyst and brought them to a gemologist for grading. One of the first things the grader will notice is the size variation. The smaller stones will settle at the bottom of the pile. This leaves the larger stones on top, demanding the most attention. Since there are fewer large stones, they’ll receive a higher grade in the size category than the smaller ones.

For amethysts, a 100-carat stone is rarer than a one-carat stone. Therefore, that feature will add to an amethyst’s value. However, simply being larger doesn’t make it better. A small person couldn’t wear such a huge stone gracefully. It wouldn’t be the best gem choice for someone with a slight build. 

Feature Rarity and Gem Grading

The rarity of quality is the main reason why some gems receive different grades. However, when the grading system was first developed, there wasn’t a lot of study on how to measure features. For example, green is a common gem property, but it’s rare in jadeite though it’s common in many other gemstones. You may have noticed that green-colored jadeite can be distinguished from other colors by its translucence and color saturation.

Green is not as rare as blue or red in jadeite, so it doesn’t get a top grade for green color as citrine does. But it’s still Grade A for the color green because it would be very rare in any other gem. This system doesn’t describe the color per se; it describes the lack thereof. Without this system, a lot of green jadeite would get an F or even G grade because not enough of it is green. With this grading system, all materials can receive a grade within a specific category such as green jadeite.

Other Properties

Under normal lighting conditions, you may see banding patterns in gemstones such as orange jadeite and red jasper that appear throughout their bodies. The banding patterns are the result of the deposition of carbon during cooling. If a gem is enhanced this way, it loses its value as a natural material. Some people will have a problem with gemstones that have obvious inclusions or flaws, and we must respect their wishes.

Gem Grading Systems

There ar many other different types of grading systems for gems that are used by other countries besides these. The standards for grading are different from company to company and country to country. However, if you’re a beginner, learning about the basic systems above is a good start. They’re the most common systems used by jewelers and the ones that you’ll see on most of the stones offered here at GIAGems.com.

The Difference between Natural and Synthetic Stones

Natural gemstones for jewelry making are stones that have been mined from the earth. That would include jade, amethyst, and citrine. This can include irradiation (usually for diamonds), heat treatment for clarity and color enhancement (usually for emeralds, rubies, sapphires, topaz, and blue topaz), as well as other treatments such as spectral treatment on colored diamonds to change the colors of these diamond simulants. Some synthetics are rarer than some of their natural stone counterparts; however, they may be more stable to take the heat.

Conclusion- 

Wearing jewelry is a fashion statement. It can also demonstrate a difference to others. We do not all have the same taste, we all have different preferences in things that we like. That’s why it is important to pay attention to what type of jewelry you wear and what people around you are wearing.

Every night without fail we go through the same routine: eating dinner, watching TV, and reading on a Kindle before going to sleep.