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Quick question re: “chrome”


Does the adjective “chrome” (e.g., chrome diopside or chrome tourmaline) just signify the presence of chromium in a gem, or is there more to it? For example, does it usually mean the gem’s color will be darker, more intense? Thanks a lot, Russ G.


A good basic question with a good basic answer … Get out your Chelsea Filter … It’s purpose is to detect the presence of Chromium in a gem as a chromophore. When chrome is present you will see pink to red through the Chelsea Filter … no chrome shows yellowish to green. Excepting rubies, most gems bearing chromium appear green to the eye. The more chromium present, the stronger the tone and or saturation of the green hue.


Yes, the prefix “chrome” indicates that there is chrome in the stone.


The one major exception to the chrome makes a gemstone green is bixbite - red emerald. Also the amount of chromium makes corundum a ruby.


Don’t forget the makes it’s green


I think the answer to your question is it depends…chrome diopside is often a dark green and large stones tend to be too dark, but it also comes in shades of green as light as lime green. Chrome tourmaline tends to be dark to too dark and is sometimes a muddy green. I don’t know of a light green chrome tourmaline, but I guess it is possible. Chromium makes emeralds green, but it doesn’t necessarily mean they will be dark or too dark. So I think the effect of chrome on the stone depends on the gem and probably various factors…


Thanks so much for all the feedback. Very helpful…and much appreciated. Russ