To observe color, you need two types of Light: daylight-equivalent and incandescent-penlight.
- The particular color of a gemstone may vary depending on the quality of the incident light, for example alexandrite will appear green in daylight and red in artificial light
- Look at the Gem face up, you need a white viewing back-ground, 5-7 inches under the light, hold it in tweezers.
Remember: always turn the object while you are viewing it and make sure you examine every part of the interior and exterior. Always vary the lighting. This enables you to notice features that may appear suddenly. Practice using light to your advantage when observing.
Combination of a Gem face-up analyzes also a hue, tone, and saturation:
HUE: The pure spectral sensation.
- A partly of Gem is yellow, mostly green. Hue will be: yellowish Green.
- Equal amounts of blue and Green will be Blue-Green or Green-Blue.