Attending the Tucson Gem and Mineral Show offers a unique opportunity to acquire precious gemstones and jewelry. To ensure informed purchases, it's essential to utilize proper tools and techniques for evaluating gemstones, pearls, and set jewelry.

Essential Tools for Gemstone Evaluation

Bringing the right tools is crucial for accurate assessment:

• Jeweler's Loupe: A 10x magnification loupe is indispensable for inspecting gemstones up close, allowing you to examine clarity, inclusions, and cut quality. I like to use a 60X loupe that also has a light source.
• Portable Light Source: A small flashlight or penlight helps in evaluating a gemstone's color and transparency.

Evaluating Rough Gemstones

When assessing rough gemstones:

1. Illumination: Place the flashlight against the side of the rough stone to observe its overall color and translucency.
2. Magnification: If the rough stone has a polished area, use the loupe to inspect for inclusions and assess clarity.

Copper Schiller in Oregon Sunstone

Evaluating Cut and Polished Loose Gemstones

For faceted gemstones:

1. Side Lighting: Shine the flashlight from the side without direct contact to observe internal features and color consistency.
2. Loupe Examination: Use the loupe to detect inclusions, assess clarity, and evaluate the quality of the cut.

Non-Destructive Testing of Pearls

To distinguish genuine pearls:

• Surface Examination: Real pearls have a slightly rough texture due to microscopic nacre layers, while imitation pearls feel smooth.
• Luster and Color: Authentic pearls exhibit depth in luster and subtle color variations, unlike the uniform appearance of fake pearls.
• Drill Hole Inspection: Genuine pearls typically show sharp edges around drill holes, whereas faux pearls may have uneven or flaking coatings.

Non-Destructive Testing of Gemstones in Jewelry

For gemstones set in jewelry:

• Visual Inspection: Use a loupe to examine the stone for inclusions, color zoning, and external blemishes.
• Lighting Techniques: Illuminate the gemstone from different angles to observe optical properties like brilliance and dispersion.

Additional Tips for the Tucson Gem Show

• Preparation: Create a list of desired gemstones and set a budget to stay focused.
• Networking: Engage with vendors and attend workshops to enhance your knowledge and experience.
• Documentation: Keep detailed records of purchases, including vendor information and gemstone specifics.

By employing these tools and techniques, you can confidently assess and purchase gemstones and jewelry at the Tucson Gem Show.

Online Resources for Gem Identification

Geminterest is an excellent free resource of information and photos of gemstone inclusions to help you identify gemstones. The language is in French so you can translate through Google Translate website feature. Bookmark this site as it doesn't show up in "gem identification" searches at all!

Barbara Smigel Gemology Course offers her online course with a SCRBD subscription. You can also access her archived course for free here.