For centuries, birthstones have held a special allure, connecting individuals to the month of their birth and evolving into prized possessions. These gemstones, now frequently found gracing collections and museums, vary significantly in value. This article explores a ranking of birthstones based on their market price, drawing upon available data regarding their properties, rarity, and desirability.
History and Lore
The tradition of associating specific gemstones with each month dates back centuries, though the specific attributions have shifted over time. Originally, the connection was often astrological, with each stone linked to a zodiac sign. As the practice evolved, a more standardized system emerged, assigning a single gemstone – or sometimes two – to each month. Today, birthstones are often chosen for their aesthetic appeal, symbolic meaning, and perceived metaphysical properties. The increasing popularity of birthstone jewelry has also driven demand, impacting market values.
The Most Expensive Birthstones
Several factors contribute to a gemstone’s value, including color, clarity, cut, carat weight, and rarity. The following ranking is based on average price per kilogram and reported sales of exceptional specimens, as detailed in available sources.
Ruby – July Birthstone
Topping the list is the ruby, the birthstone for July. Sources indicate an average price of $3,500,000 per kilogram, with the most expensive ruby ever sold reaching $14.2 million. Ruby’s value is intrinsically linked to its vibrant red hue, a result of the presence of chromium. The finest rubies, known as “pigeon’s blood” rubies, exhibit a pure, intense red color. Rubies, a variety of the mineral corundum, rival sapphires in hardness, scoring a 9 on the Mohs scale.
Sapphire – September Birthstone
Following closely behind is the sapphire, representing September. With an average price of $1,750,000 per kilogram and a record sale of $6.7 million, sapphires are highly sought after. While most commonly known for their blue color, sapphires actually occur in a wide range of hues, referred to as “fancy sapphires.” Kashmir sapphires, originating from the India-Pakistan border region, are particularly prized for their exceptional color saturation. Like ruby, sapphire is a variety of corundum and boasts a Mohs hardness of 9.
Tanzanite – December Birthstone
December’s birthstone, Tanzanite, occupies the fifth position in this ranking. Averaging $1,000,000 per kilogram, with exceptional stones reaching $3.3 million, Tanzanite is a relatively recent addition to the birthstone family. Its distinctive purple hue sets it apart, though its relative softness – scoring 6-6.5 on the Mohs scale – makes it more suitable for collector’s items than everyday jewelry. Tanzanite’s rarity is a key factor in its value, as it is found in only one small region of Tanzania.
Diamond – April Birthstone
Diamonds, the April birthstone, are valued between $3,500 and $10,000 per carat. The most expensive diamonds are colorless, large in size, and possess the highest ratings for color (D through F) and clarity (Internally Flawless). Type IIa diamonds, free of nitrogen and boron impurities, are particularly coveted. Fancy color diamonds, such as red, green, purple, orange, pink, and blue, are also highly valued, with the rarest colors commanding the highest prices.
Mid-Range and More Affordable Options
Beyond these top-tier gemstones, a range of other birthstones offer beauty and value at more accessible price points.
Topaz – November Birthstone
November’s birthstone, Topaz, is found naturally in a variety of colors, including yellows, pinks, oranges, and browns. While natural blue topaz exists, much of the blue topaz on the market has been irradiated to achieve its color. Topaz has a Mohs hardness of 8, making it a relatively durable gemstone. However, it possesses a cleavage plane that can cause it to shear if struck forcefully. Properly cut stones minimize this risk. Major sources of topaz include Brazil, Mexico, and Sri Lanka.
Zircon – December Birthstone
Zircon, another December birthstone, is known for its brilliance and is often used as a diamond substitute. It occurs in a variety of natural colors and has a Mohs hardness of 6.5-7.5.
Garnet – January Birthstone
January’s birthstone, Garnet, is available in several colors, with red being the most popular. Garnet symbolizes passion, energy, and good health. It typically scores between 6.5 and 7.5 on the Mohs scale.
Amethyst – February Birthstone
February’s birthstone, Amethyst, is a deep, rich purple gemstone. Historically, amethyst was considered as valuable as ruby and sapphire, symbolizing peace, clarity, and spiritual growth. It has a Mohs hardness of 7.
Aquamarine – March Birthstone
Aquamarine, the birthstone for March, scores 7.5–8 on the Mohs scale.
Peridot – August Birthstone
August’s birthstone, Peridot, is unique in that it is typically found in only one color: lime green. It symbolizes strength, protection, and healing. Peridot has a Mohs hardness of 6.5-7.
Opal – October Birthstone
October’s birthstone, Opal, is sourced primarily from Australia, Mexico, and Idaho. It scores 5.5–6.5 on the Mohs scale.
Citrine – November Birthstone
Citrine, another November birthstone, is available in yellow and orange colors, symbolizing joy, abundance, and prosperity.
Tourmaline – October Birthstone
Tourmaline, also representing October, comes in a wide range of colors, including pink, green, and bi-color options, symbolizing creativity, love, and healing.
Gemological Properties and the 4Cs
The cost of birthstones, regardless of their position in the ranking, is ultimately determined by the “4Cs”: Color, Cut, Clarity, and Carat. Color refers to the hue, tone, and saturation of the gemstone. Tone describes the lightness or darkness of the color, while saturation refers to the intensity. Clarity refers to the presence of imperfections, both internal and external. Carat refers to the weight of the gemstone, with larger stones generally commanding higher prices, provided the other 3Cs are equal.
Purchasing Considerations
When selecting birthstone jewelry, it is advisable to consider the durability of the gemstone, as indicated by its Mohs hardness. Softer stones, such as Tanzanite and Opal, are more prone to scratching and may be better suited for occasional wear. Additionally, opting for a gemstone certified by a reputable organization, such as the Gemological Institute of America (GIA), ensures authenticity and quality.
Sources
Conclusion
The world of birthstones is rich in history, lore, and geological wonder. From the highly prized ruby and sapphire to the more accessible topaz and amethyst, each gemstone possesses unique qualities that contribute to its value and appeal. Understanding the factors that influence a gemstone’s price, including the 4Cs and its inherent properties, empowers enthusiasts and buyers to make informed decisions and appreciate the enduring beauty of these natural treasures.