Chromium Oxide

Product Details:

Chromium oxide is a green-colored polishing agent used in lapidary work, particularly for gemstones with Mohs hardness between 5 and 8. It's effective for achieving a mirror-like finish on stones like emeralds, quartz, jade, and garnet. Chromium oxide is also responsible for the green color in gemstones like emeralds and can contribute to the green hues in other gems like tourmaline and garnets. 
Here's a more detailed look:
Uses of Chromium Oxide in Gemstone Polishing:
Polishing Agent:
Chromium oxide is used as a polishing compound on laps (rotating surfaces) to smooth and polish gemstones.
Ideal for Softer Stones:
It's particularly well-suited for stones with hardness values in the range of 5 to 8 on the Mohs scale.
Mirror Finish:
When used correctly, chromium oxide can produce a high-quality, mirror-like polish on gemstones.
Variety of Gemstones:
It can be used to polish various gemstones, including emeralds, quartz, jade, garnet, aquamarine, beryl, tourmaline, Tanzanite, and others. 
Chromium's Role in Gemstone Coloration:
Emeralds:
Chromium is a key element responsible for the green color of emeralds, which are a variety of beryl. 
Rubies:
While not a colorant in rubies, chromium is responsible for the red color in these gemstones. 
Other Gemstones:
Chromium can also contribute to green colors in other gemstones like tourmaline and garnets, such as tsavorite. 
Color Change Phenomenon:
In some gemstones, like alexandrite, chromium can cause a color-change effect, making the gem appear green in certain lighting conditions and red in others. 
Key Characteristics of Chromium Oxide:
Color: Green.
Hardness: Chromium oxide has a hardness that allows it to effectively polish gemstones.
Availability: It's available in various forms, including powder and compound-infused laps.