Ruby fuchsite and ruby zoisite are two similar looking gemstones that are often confused with one another. However, there are some key differences between these two types of ruby that allow them to be distinguished.
Ruby Fuchsite
Ruby fuchsite is a type of ruby that contains traces of green fuchsite within it. Fuchsite is a chromium-rich muscovite mica that has a distinctive emerald green color. The combination of the rich red ruby color and the green fuchsite inclusions gives ruby fuchsite an attractive dual color that is highly prized.
While most natural ruby is found in an aluminum oxide mineral called corundum, ruby fuchsite differs in that the corundum contains flakes of fuchsite mica embedded in it. The fuchsite usually occurs in fine flakes throughout the corundum, giving the stone a distinctive greenish shimmer across the surface when viewed from different angles.
Ruby fuchsite is somewhat rarer than normal ruby. The dual coloration of red and green makes this stone popular for jewelry purposes. India is the main source location for ruby fuchsite, particularly in Southern India in a region called Karur. Some rubies from Tanzania and Kenya also exhibit fuchsite inclusions.
The green tint from the fuchsite makes ruby fuchsite exhibit a more muted and darker red color than pure ruby. But when finely faceted, the contrast between the red and faint green can be quite beautiful and unique.
Ruby Zoisite
In contrast to ruby fuchsite, ruby zoisite actually consists of two separate minerals – ruby and green zoisite. While ruby fuchsite has the fuchsite mica embedded within the corundum, in ruby zoisite the ruby and zoisite form distinctly separate but parallel intergrown crystals.
Zoisite is a calcium aluminum silicate mineral that can form opaque mass colored gemstones when it contains traces of transition metals like chromium or vanadium. The green zoisite commonly intergrown with ruby usually gets its color from traces of chromium or vanadium. When viewed with a microscope, the difference between the red ruby and green zoisite crystals is very apparent.
The combination of emerald green zoisite with rich ruby red results in a distinctive bicolored stone. While India does produce some ruby in zoisite, most ruby zoisite on the market comes from Tanzania. Occasionally ruby zoisite is also found in Kenya as well as in Myanmar.
Distinguishing Features
While both ruby fuchsite and ruby zoisite exhibit an attractive mix of ruby red and green colors, there are distinguishing features that allow them to be differentiated:
- Ruby fuchsite has the green fuchsite mica embedded directly within the ruby corundum, while in ruby zoisite the green zoisite forms distinctly separate crystals from the ruby.
- Under magnification, ruby fuchsite usually shows fine green flakes and spots distributed across the stone, while ruby zoisite shows an intergrown mix of opaque red and green crystals.
- The green color in ruby fuchsite has a more subtle sheen compared to the opaque green of zoisite. The red color of ruby zoisite tends to be somewhat more muted compared to ruby fuchsite.
- Ruby zoisite is dichroic, meaning it can display different colors from different viewing angles. Ruby fuchsite does not show this dichroic effect.
- Ruby fuchsite most often occurs in cabochon form to show off the stone's optical effects, while ruby zoisite commonly occurs as faceted gemstones.
So, ruby fuchsite is a single corundum mineral with fuchsite inclusions, while ruby zoisite consists of two separate intergrown minerals. Examining the distribution of the green and red colors as well as the stone's optical effects allows these two bicolored gemstones to be distinguished. Both offer beautiful and unique color combinations.
