Most Valuable Birthstones, Ranked
Birthstones have been fascinating people for centuries. They've since evolved into priceless collector's items, with the most valuable gemstones appearing in museums like the Smithsonian.
Top-quality gemstones from each month are worth a pretty penny, but which birthstone is worth the most?
These are the most valuable birthstones, ranked by their average price. Plus what makes each one unique and the most expensive birthstones on record.
Month peridot represents: August
Average price: $500/kg
Most expensive peridot stone: ~$18,000
Note: Value estimates are based on the average price of each gemstone per kilogram at the time of publication. Exact values vary depending on the cut and quality of each gem, as well as changing market value. Current figures are based on information from Gemval.
Bottom Line: Peridot
Peridot, the light green August birthstone, is also known as chrysolite. While gem collectors typically go for the more valuable green gemstone, emerald, peridot is impressive all on its own.
It's lighter, more olive-toned color can be strikingly rich, and completely clear specimens are often turned into expensive jewelry. One of peridot's unique qualities is that its shimmer is visible even under artificial lighting, unlike most other gemstones that appear much duller indoors than in sunlight.
This has earned it the nickname "the evening emerald."
Month amethyst represents: February
Average price: $600/kg
Most expensive amethyst: ~$300,000-$400,000
Bottom Line: Amethyst
Amethyst is one of the few birthstones that can be found everywhere from mom and pop crystal and mineral shops to souvenir stores. It has a hardness of 7 on the Mohs scale, the same as that of quartz, which is plenty hard enough to use in jewelry.
It's much more affordable than most gemstones, but large crystals can be worth thousands. Crystals with a deep, red-purple hue are also valuable.
Month topaz represents: November
Average price: $24,000/kg
Most expensive topaz: ~$148,800
Bottom Line: Topaz
Topaz, a mineral made of silica, comes in almost every color and shade. Its hardness of 8 makes it ideal for virtually any type of jewelry, and it's fairly affordable compared to some other birthstones. While colorless topaz is virtually worthless, red, blue and orange topaz are quite valuable.
Like all gemstones, naturally vibrant, highly pigmented topaz specimens are the most prized, and their value increases with size. Brazil is currently the largest producer of natural topaz, although there are also topaz mines in India, Pakistan, Russia and China.
Month garnet represents: January
Average price: $400,000/kg
Most expensive garnet: ~$316,000
Bottom Line: Garnet
Sorry, January babies. Garnets are often considered off-brand rubies, but they're pretty underrated. They come in a wide range of colors, and red garnets are the most popular. They tend to be less clear and more orange-tinted than rubies. They're also not nearly as durable.
Still, they're valuable in certain forms, and can be made into more affordable jewelry than rubies. The largest garnet found so far weighs 3,956 carats and is owned by the Medici Collection, LLC (USA) as of March 9, 2020.
The Medici family has held several rare gems and minerals for generations.
Month emerald represents: May
Average price: $500,000/kg
Most expensive emerald: $5.5 million
Bottom Line: Emerald
If the Wizard of Oz collects real emeralds, he's doing pretty well for himself. Emeralds, the May birthstone, are a shiny shade of forest green, sometimes leaning more toward teal. They're a variety of the mineral beryl, but only deeper shades are considered true emeralds.
Emeralds have a hardness of 7.5-8, making it one of the hardest gemstones just below rubies and sapphires. Like most gemstones, the darker the color, the more valuable the emerald. Because most emeralds have inclusions, or imperfections, a clear emerald is even more valuable.
Most premium emeralds come from Colombia, but they've been found in Russia and the U.S. as well. The Rockefeller emerald is the most expensive emerald sold to date, going for $5.5 million in 2017.
Month opal represents: October
Average price: $700,000/kg
Most expensive opal: $1 million
Bottom Line: Opal
The opal, also known as the October birthstone, can be anything from utterly ordinary to downright jaw-dropping. It comes in several color varieties and patterns, and precious opal from Australia is the most valuable. High-quality opals exhibit a "play-of-color," or flashes of multiple colors that appear when the gem is moved about under light.
Australia produces over 90 percent of the precious opal worldwide, and it's the country's national gemstone. Black opal, white opal and fire opals are among the most valuable.
The Virgin Rainbow Opal is considered the most valuable opal. Discovered in 2003, it is owned by the South Australian Museum and is valued at around $1 million. It also supposedly glows in the dark.
Month aquamarine represents: March
Average price: $750,000/kg
Most expensive aquamarine: ~$1.5 million
Bottom Line: Aquamarine
Aquamarine glows in a pale shade of green-blue. It varies in color from pale blue to aqua. While it's not the most rare gemstone, large, clear crystals can be extremely valuable. Some stones in Brazil have been found weighing over 500,000 carats.
Thanks to its durability, ranking 7.5-8 on the Mohs scale, it's a good gemstone for use in necklaces and rings. The icy blue March birthstone can be found in several countries, but the most richly colored specimens are usually found in Madagascar.
Month tanzanite represents: December
Average price: $1,000,000/kg
Most expensive tanzanite: ~$3.3 million
Bottom Line: Tanzanite
Tanzanite, another of the most valuable gemstones, is made of the mineral zoisite. It's softer than sapphire with a hardness of 6-6.5 on the Mohs scale, and its coloration has more of a purple hue. Because of its relative softness, it's infrequently used in jewelry.
Instead, tanzanite crystals are used mostly as collectible display pieces. The saturation and color shift depending on the angle you look at it. Some are heat-treated to emphasize the color, but natural, dark blue tanzanite stones are the most valuable.
Its value is partly due to its rarity. So far, tanzanite has only been found in a small region in Tanzania.
Month sapphire represents: September
Average price: $1,750,000/kg
Most expensive sapphire: $6.7 million
Bottom Line: Sapphire
Sapphire, the blue version of the mineral corundum, is the most sought-after blue gemstone. It's also the September birthstone, and it's tied with ruby on the Mohs hardness scale. While blue is the most popular color, other colors of sapphires exist, often known as "fancy sapphires."
The value of a sapphire is largely determined by the saturation and depth of its color. The richer the blue hue, the more valuable the gemstone. Kashmir sapphires, found along the border of India and Pakistan, are the most highly pigmented and smooth, and they're also among the rarest.
Month ruby represents: July
Average price: $3,500,000/kg
Most expensive ruby: $14.2 million
Bottom Line: Ruby
The July birthstone boasts the most vibrant red hue of any gemstone. Rubies have an intense red color and impressive durability, with a hardness of 9 on the Mohs scale. Only diamonds are harder, making rubies an excellent choice for jewelry.
Rubies are a variety of a mineral called corundum, just like sapphire. The only difference between the two are the impurities found in the mineral, which alters their color and composition. The larger, clearer and more colorful the ruby, the greater its value. Natural rubies are considerably more valuable than synthetic rubies, and some produce a star-like refraction of light when polished.
The Jubilee Ruby is one of the most valuable colored gemstones sold in the U.S., weighing 15.99 carats and selling for $14.2 million.
Month alexandrite represents: June
Average price: $5,000,000/kg
Most expensive alexandrite: ~$100,000
Bottom Line: Alexandrite
Alexandrite, composed of beryllium, is one of the hardest gemstones available, with a Mohs rating of 8.5. The greenish-hued June birthstone changes color in the light, turning a reddish hue in artificial lighting. The more dramatic the gemstone's color shift, the more valuable it is.
Alexandrite is also valuable because of how difficult it is to find. Most alexandrite gemstones are under two carats, but the largest cut alexandrite on record measures a startling 141.92 carats.
Month diamond represents: April
Average price: $6,000,000/kg
Most expensive diamond: $71.2 million
Bottom Line: Diamond
Diamond, the April birthstone, is the most recognizable gemstone in the world. It's entirely made of carbon, and its remarkable hardness is one of the qualities that makes it so valuable. It's virtually impossible to scratch, but its brittleness makes it a challenge to cut without shattering it.
Diamonds refract light easily, resulting in the sparkling quality they're so famous for. Industrial grade diamonds aren't all that rare, but gemstone quality ones are tough to find. Colorless diamonds are the most common, but diamonds come in numerous colors. The most vibrantly colored ones are the most expensive.
The Pink Star diamond, last sold in Hong Kong in 2017, is known as one of the rarest gems in the world.