•What is ruby?
Ruby is the red variety of gem-quality corundum. (The mineral corundum occurs in a wide range of colors, but all corundum that is not the color red is called sapphire. See the chapter on sapphire in this volume.) Ruby has long been prized as the “king of gems” and the “gem of gems” and it is one of the three natural gemstones that comprise the previously described trinity of precious stones, the other two being emerald and sapphire. (Diamond is, of course, in a category all its own!) Ruby is beautiful, extremely hard, and is one of the gemstones most well-suited for use in jewelry. Ruby is the July birthstone and is the commemorative gemstone for the 40th wedding anniversary.
•Where is ruby found?
Rubies are found in Myanmar (the finest specimens), Sri Lanka, Thailand (brownish red stones), Afghanistan, India, Kampuchea, Pakistan, Vietnam, Norway, Kenya, Tanzania; and North Carolina in the United States.
•Color
Ruby occurs in shades of red, including bright red, purplish red, brownish red and pinkish red. Usually the stones with the deeper and more consistent color throughout are considered the most attractive and are the most valuable.
•Shape
Ruby is extremely suitable for cutting into all the faceted gemstone shapes: round brilliant, oval, pear, marquise, emerald, heart, square, trillion, and fantasy. Ruby is also cut into cabochons, and some translucent forms of ruby exhibit a six-line star effect in the middle (from the presence of internal rutile inclusions) when cut as a cabochon. These gorgeous, intriguing stones are known as star rubies.
•Durability
Ruby is an exceptionally durable stone. It can stand up to polishing, boiling, ultrasonic cleaning, a jeweler’s torch, steaming, and many other treatments. It is a 9 on the Mohs Scale, meaning that only diamond is harder. Thus, rubies can be worn with confidence and can stand up to daily wear in rings, pendants, earrings, and other uses. That said, though, please always remember that any gemstone -- including ultrahard diamonds -- can chip, crack, or even fracture if struck just right. Thus, you should not wear any of your gemstone jewelry when doing anything during which you might accidentally bang the stone against a hard surface.
•Quality
The quality of ruby is determined much the way we evaluate the quality of a diamond: by its color and internal inclusions. The highest quality rubies are a deep red color and “eye clean”; i. e., there are no inclusions (flaws) visible to the naked eye. Color evaluation then scales down to fine color, good color, fair color, etc. Clarity (also sometimes referred to as quality) evaluation likewise scales down to minor inclusions, but still almost eye clean; to visible inclusions; and, ultimately, to heavily included. The large, top red, internally flawless rubies are the scarcest, the rarest, and therefore, the most valuable.
•Legend and lore
Rubies have long been thought to bring health, financial success, wisdom, and success in love to its wearers. Ruby has also been associated with passion (probably because of its fire-red color?), and some of the ancients attributed magical powers to rubies, believing that the gemstone’s red color would fade if its wearer was in danger or ill health. Ruby can also reputedly enhance the natural beauty of its wearer; and ruby can also bring a sense of joy to the wearer about being of service to others.
•Care
Ruby jewelry can be cleaned in standard jewelry cleaner, at close to boiling temperatures, and is quite resistant to scratches. Soak it in the jewelry cleaner and then rinse the jewelry well under hot water. As with most other natural gemstones, avoid extreme and drastic temperature changes; for instance, do not boil ruby or expose it to extreme heat (such as that of a blow dryer) and then run it under cold water. Other than that caution, though, ruby can be safely cleaned in cleaning solutions that night harm softer stones. (Note: As previously indicated, ruby is hard. This means that if a ruby is rubbed or scraped against a softer stone, it could actually scratch the stone. Store your ruby jewelry away from your other jewelry so the pieces do not touch each other.)