Lesson 2: Ultraviolet Testing and Gemstone Identification


Step 3: Practical Gemology

Lesson 17

Additionally, ultraviolet testing can expose some gemstone treatments and assembled stones. The enhanced layers of diffusion-treated gems, oils used as fillers in emeralds and other gems, and the components of assembled stones often have different fluorescent qualities than the rest of the specimen material. Seeing this at an early stage of your examination can save time later.

A Warning About Ultraviolet Testing

Never look at your ultraviolet (UV) light. Shortwave (SW) UV light can damage your eyes, even to the point of blindness. If you’re ever unsure if your UV light source is on, check the switch. Better yet, a flame-fusion ruby will tell you instantly if the light is on or not.

Ultraviolet Testing Tools

Just beyond the visible light spectrum lies infrared and UV light. For gem identification, we use longwave (LW) light, 315 to 400 nm, …

Every Gemstone Is Unique - Here's How The Experts Evaluate Them

in this training-course, discover the tools, tests & valuation process used by expert gemologists for colored gemstones, opals & diamonds

Course: Hands-On Gemology: Gemstone Identification Grading & Testing
Purchase Course: $79.00
Skill Level: Intermediate - Advanced
Lessons: 60
Time: 480 min