22.40ct Spiral Carved Ruby Cabochon 17mm

Ruby’s hues vary from orangey-red to purplish-red and the presence of chromium is the trace element that causes the unparalleled ruby red colour. The most valuable colour is the “pigeon’s blood” variety which is a vibrant red without any orange or purple tint. The name “ruby” derives from the word “ruber” that means “red” in Latin and it is the most valuable variety of the corundum species. Some rubies display the gemmological phenomenon called “asterism” where cabochon-cut stones have a whitish star on top of the dome. This is created by fine intersecting rutile needle inclusions. One interesting thing that you might find in some rubies is an inclusion also knows as “silk” consisting of fine intersecting rutile needles. Most rubies that come from marble deposits fluoresce a strong red under long wave ultraviolet light while the ones that come for basalt or metasomatic deposit are usually inert because of their high levels of iron.;Stone Size: 17;Carat Weight (ct): 22.4