Tourmaline
| Property | Details |
|---|
| Mineral | Tourmaline (boron silicate) |
| Mohs Hardness | 7 – 7.5 |
| Refractive Index | 1.624 – 1.644 |
| Birthstone | October |
| Anniversary | 8th |
| Major Sources | Brazil, Mozambique, Nigeria, Afghanistan, Maine & California (USA) |
| Treatments | Heat treatment for some colors; Paraiba often heated |
Overview
Tourmaline is one of the most colorful gemstone families, occurring in virtually every color and even in multicolored crystals. Its extraordinary color range makes it a favorite of gem collectors and jewelry designers alike.
Major Varieties
Paraíba tourmaline: A neon blue-green caused by copper, among the world's most valuable colored gemstones. Discovered in 1989 in Paraíba, Brazil, with additional deposits found in Mozambique and Nigeria. Fine Paraíba can exceed $50,000 per carat. Rubellite: Red to hot pink, the most valued variety after Paraíba. The finest display a vivid cranberry red. Indicolite: Blue tourmaline, from pale to deep blue. Chrome tourmaline: Vivid green colored by chromium, found in East Africa. Watermelon tourmaline: Pink centers with green rims in a single crystal, often sliced into cross-sections for jewelry. Bi-color and parti-color: Multiple colors in a single crystal.
Quality & Value Factors
Color saturation is the primary value driver. Paraíba commands the highest prices due to its unique neon color and extreme rarity. After Paraíba, rubellite (red) and fine indicolite (blue) are most valued. Clarity expectations vary by color—red and pink tourmalines are expected to have more inclusions than green or blue varieties. Cut quality is especially important for tourmaline because the crystals are strongly pleochroic.
Care & Cleaning
Tourmaline ranks 7 to 7.5 on the Mohs scale and is suitable for all types of jewelry. Clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners for heavily included stones. Tourmaline can become electrically charged when heated (pyroelectricity), which can attract dust.
Frequently Asked Questions
What is Paraiba tourmaline?
Paraiba tourmaline is a copper-bearing tourmaline that displays a unique neon blue-green color unlike any other gemstone. First discovered in 1989 in the state of Paraiba, Brazil, it quickly became one of the world's most valuable colored gemstones. Similar copper-bearing tourmalines have since been found in Mozambique and Nigeria. The term Paraiba is now used as a variety name for any copper-bearing tourmaline with neon blue-green color, regardless of geographic origin. Fine Brazilian Paraiba can exceed $50,000 per carat.
What is watermelon tourmaline?
Watermelon tourmaline is a multicolored variety that displays a pink or red center surrounded by a green rim, resembling a slice of watermelon. This occurs naturally when the chemical conditions change during crystal growth. Watermelon tourmaline is typically sliced into thin cross-sections and polished to display the color zoning, then set in jewelry as slices or cabochons. It is a collector favorite and a unique choice for one-of-a-kind jewelry pieces.
Is tourmaline durable for everyday jewelry?
Tourmaline ranks 7 to 7.5 on the Mohs hardness scale, making it suitable for most types of jewelry. It has no cleavage concerns and good toughness. Tourmaline works well in rings, earrings, pendants, and bracelets for everyday wear. The only precaution is to avoid hard impacts and remove tourmaline rings during heavy physical activities. With normal care, tourmaline jewelry will last a lifetime.
Why are tourmaline colors so diverse?
Tourmaline's extraordinary color range comes from its complex chemical composition. It is a boron silicate mineral that can incorporate many different elements into its crystal structure, including iron, manganese, chromium, vanadium, copper, lithium, and others. Each element or combination produces different colors. Iron creates green and blue tones, manganese produces pink and red, chromium gives vivid green, and copper creates the neon blue-green of Paraiba. This chemical flexibility is why tourmaline occurs in more colors than any other gemstone.
What is the most valuable type of tourmaline?
Paraiba tourmaline is by far the most valuable variety, with top specimens exceeding $50,000 per carat due to their unique neon blue-green color and extreme rarity. After Paraiba, fine rubellite (vivid red-pink) and chrome tourmaline (vivid green) are the most valuable. Indicolite (blue) tourmaline also commands good prices for saturated, vivid stones. The value of any tourmaline depends primarily on color saturation, clarity, and size.
Specialty & Collector Gemstones