Ruby Jewelry Rubies, the birthstone for May, is a red gemstone which comes in shades of dark pink to blood red to dark purple. Rubies are of the most rarest gemstones in the world. They are found in Myanmar, Kenya, and Sri Lanka. At Two Tone Jewelry Mfg. Co., we only carry the finest Ruby gemstones. Our Ruby gemstone jewelry is 100% natural and comes set in 14kt and 18kt Gold. Each and every piece of Ruby Jewelry is assembled with care and every gemstone is handpicked by industry experts.