What’s the difference between a reflectometer and a refractometer? If you’re interested in studying or buying gems, learn the facts here.…
The Usambara effect is a gemstone color change phenomenon distinct from pleochroism or the alexandrite effect. Tourmaline and other species…
A classic chameleon diamond can change color from green to yellow under certain conditions. Learn more about this process and other color change…
Diamonds may form under intense heat and pressure, but under what conditions can diamonds burn? Learn the science behind a diamond’s fiery end.…
Fuzzy refractometer readings may be the result of poorly faceted gems, the wrong amount of refraction liquid, and even stone size. Learn more here.…
The glass used to make refractometer hemicylinders is susceptible to tarnish. Here’s a step-by-step guide for re-polishing a refractometer…
Novice and expert gemologists discuss their experiences at the celebrated annual February Tucson Gem and Mineral Show. You’ll find reviews of…
A gemstone’s clarity grade indicates how free it is of inclusions and blemishes. Learn how to decipher the GIA clarity grading codes and types.…
Aquamarine is the blue to blue-green variety of beryl. If you encounter so-called white aquamarines, buyer beware. Learn the facts about these…
What’s the difference between a lab-created emerald and a natural emerald? Is a synthetic gem a real gem? Learn the facts before you buy emerald…
Both natural and synthetic rubies fluoresce under UV light. Learn how slight differences in fluorescence patterns can help gemologists distinguish…
How does faceting affect gem value? Custom-cut gemstones are unique pieces and command a high price. Learn how custom cutting compares to factory…
NGOs and movies have helped raise awareness of conflict diamonds, and governments have taken steps to stop their trade. How effective are these…
A number of online sites have reported on a large emerald, supposedly recently extracted from the Chivor mine in Colombia. However, is this apparently…
The GIA grading system describes gem color in terms of hue, tone, and saturation. Learn what the abbreviations and numbers of this gem grading code…
Appraising gemstones requires experience and an in-depth knowledge of gems. A list of gemstone wholesale prices is one element used in appraisals.…
Do you have an offer for bargain rubies that’s too good to be true? Learn what you need to know before you buy and avoid high-pressure sales tactics.…
Some opals from Spencer, Idaho show asterism or the “star stone” effect. Learn how to price these beautiful but rare star opals.
Uranium glass, or Vaseline glass, is a prized collector’s item and is generally safe to handle. But is it safe to facet? Learn about the potential…
Flint and mozarkite are types of chert. While flint is known for its practical use, mozarkite is a colorful variety of chert that can be made into…
In Exodus, the breastplate of Aaron was said to hold 12 gems. However, the gemological identities of the stones, like jacinth and sapphire, are…
Turkey’s gemstones include well-known species such as diaspore, chalcedony, and jade, as well as unusual specimens of lesser-known gems. Learn…
An inexpensive pocket spectroscope can be great for student gemologists as well as pros who need to identify gems while traveling. Learn the basics…
These cleaning tips will make polishing silver jewelry a little easier. Learn how to prevent tarnish and how to clean silver and pearl jewelry,…
Agate stones typically form slowly in the cavities of ancient hardened lava flows. Learn where you can see this process occurring today.
Opals should be handled with care. If you buy opals that have been kept in water, follow these instructions to dry them safely.
Natural alexandrite is rare, creating a market for synthetics. But are synthetics real alexandrite? Learn about natural, synthetic, and real…
Golden beryl, also known as heliodor, can display rich colors and is an excellent gem choice for jewelry. Learn more about this golden relative…
Did you know most gem species can be distinguished without the element of color? Learn the role gemstone colors play in gem identification.
Will wearing gemstones so they touch your finger bring you health benefits? Learn what to look for in a ring stone.
Learn what factors most influence a sphalerite appraisal and what kind of jewelry will best showcase this beautiful gemstone.
Should you wear chrysoprase jewelry only at night to protect the gem’s striking green color? Learn the facts here.
Opal jewelry is lovely, but aren’t these gems prone to scratching and breaking? Learn the best ways to wear these colorful but delicate stones.…
IGS Become Member