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What is the best incandescent penlight for the inspection of alexandrites

Of course, the best light for the inspection of the colour change effect of alexandrites is the candle light. But, we can’t always bring the candle light. So, we need an adequate incandescent flashlight/penlight for alexandrites.

So, which one is the most recommendable one for the inspection of color-change stones? Is the incandescent flashlight sold in G.I.A Store could be a good option?

Thank you.

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Seat of the pants gemologist here. I think you could go to a thrift store and find an old flashlight with an old bulb. The dimmer the bulb, the more likely it is warm white. The newer Xenon bulbs that came right before LEDs were probably cooler light. Some of the LED bulbs may be warm white, but my experience is that they are a cooler color temperature. If I were you I would get some color change material…perhaps a synthetic, and try various lights with it until you get the biggest color change from cool to warm light. You can certainly use a warm 2700K CFL as a control for the warmest light. The color temp is noted on the package and probably on the bulb. It would be nice if you could find a warm LED, since they have the most output and efficiency. IDK whether you will find that kind of data for those lights on Amazon or wherever. -royjohn

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I use a pelican incandescent penlight for my spectroscope no extra lines like from LED light

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Thank you sir. Actually, I tried 3000k penlight before but it was not enough to inspect the colour change of the alexandrite? How do you think about to use 1500~1800k light bulbs which would be the most familiar light temperature with candle light.

Thank you.

The sources I checked all described a color change under incandescent vs daylight. A typical alexandrite is going to show a color change under incandescent light occasioned by an absorption band at 580 nm. Incandescent light is usually described as having a color temperature of 2700 to 3500K. If you do not see a good color change with light of this color temperature, IDK whether going to a 1500-1800K source is going to produce one or not. If the gem in question doesn’t show a color change at 2700K, I would think that would affect the valuation, as it isn’t typical to go hunting around for a candle or special 1800K light bulb to show the color change. -royjohn

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This one?

Pelican 1900 nemo thanks

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