Rubies are the red variety of the mineral corundum and stands as one of the four precious gemstones alongside diamond, emerald, and sapphire. This aluminum oxide crystal derives its vibrant red color from trace amounts of chromium, with the finest specimens displaying a pure red hue known as "pigeon's blood." Rubies have been treasured throughout history as symbols of passion, power, and protection, commanding some of the highest prices per carat in the gemstone world, especially for untreated specimens with exceptional color and clarity.
Specifications:
- Color range: Light pink-red to deep crimson, with the most prized being pure red without secondary hues of orange, purple, or brown
- Hardness: 9 on Mohs scale (second only to diamond, making it extremely durable for all jewelry applications)
- Origin: Myanmar (Burma), Thailand, Sri Lanka, Madagascar, Mozambique, Tanzania, and Vietnam
- Sizes: Available from small melee stones (under 0.25 carats) to rare large specimens (over 5 carats), with most quality rubies under 3 carats
- Shapes: All traditional faceted cuts including oval, cushion, round, emerald, and pear shapes, plus cabochons for star rubies
- Clarity: Ranges from eye-clean to heavily included, with natural inclusions (silk) often indicating untreated status
- Special properties: Exceptional brilliance and fire, some specimens display asterism (star effect), strong fluorescence under UV light
- Treatments: Heat treatment common to enhance color and clarity, with untreated specimens commanding premium prices
