Birthstones have fascinated humanity for centuries, not only for their aesthetic appeal but also for their symbolic and cultural significance. While most people are familiar with their own birthstone, few know which of these precious gems command the highest prices on the market. The value of a birthstone is determined by a combination of factors: rarity, color, clarity, carat weight, and historical or cultural prestige. In the world of gemology, certain stones stand out for their exceptional worth, with prices reaching into the millions of dollars per carat. This article delves into the most expensive birthstones, examining their properties, origins, and the reasons behind their astronomical market values.
Introduction
When we think of expensive gemstones, diamonds often come to mind. However, the birthstone world presents a different hierarchy of value. Among the 12 months, several birthstones have emerged as particularly costly, with prices that often surpass even those of diamonds. The most expensive birthstones include alexandrite, ruby, sapphire, emerald, and tanzanite—each with its own unique story of formation, cultural symbolism, and gemological properties. These stones are not only prized for their beauty but also for their scarcity and the difficulty involved in mining and cutting them. Understanding the factors that influence their price can help collectors, investors, and jewelry enthusiasts make informed decisions when considering these rare and valuable gems.
This article explores the most expensive birthstones in detail, including their historical significance, geological properties, and current market values. We will also examine the key factors that contribute to their high price tags and provide practical advice on how to care for these precious gems.
History and Lore
The practice of associating gemstones with specific months of the year dates back to biblical times. In the Old Testament, it is mentioned that Moses crafted a breastplate for Aaron, the high priest, which featured twelve stones representing the twelve tribes of Israel. Over time, this tradition evolved into the modern concept of birthstones, where each month is linked to one or more specific gemstones. While the exact origins of this practice are unclear, it has become a global phenomenon, with different cultures adding their own interpretations and symbolic meanings.
In the 19th century, alexandrite was discovered in the Ural Mountains of Russia. Named after Czar Alexander II, who was born on the day of its discovery, this gemstone quickly became a symbol of Russian nobility. Its unique color-changing properties—shifting from green in daylight to red in incandescent light—made it highly desirable and eventually contributed to its status as one of the most expensive birthstones.
Rubies, on the other hand, have been revered for centuries across various cultures. In ancient times, they were believed to bring protection, vitality, and even immortality. Their deep red color was associated with life and power, and they were often used in royal regalia. The 15.99-carat Jubilee Ruby, which sold for $14.2 million in 2016, is a testament to the enduring allure and value of this gemstone.
Sapphires have similarly enjoyed a long and storied history. Used by royalty in medieval Europe, they were thought to promote wisdom and virtue. The most prized sapphires come from Kashmir, where their color is described as a deep, velvety blue. This quality, combined with their rarity, contributes to their high market value.
Geological Formation and Sources
The high value of certain birthstones is largely due to their geological rarity and the conditions under which they form. For example, alexandrite is a variety of chrysoberyl, a mineral that forms under specific temperature and pressure conditions. It is only found in a few locations around the world, including Brazil, Sri Lanka, and Madagascar. The color change in alexandrite is caused by the presence of trace amounts of chromium in its crystal structure, which affects how light is absorbed and reflected.
Rubies are a variety of corundum, a mineral composed of aluminum oxide. The red color in rubies is due to the presence of chromium or vanadium. The most valuable rubies are found in Myanmar (formerly Burma), where the geological conditions are ideal for producing high-quality stones with a deep, saturated color. The Mogok region in Myanmar has long been known as the source of some of the finest rubies in the world.
Sapphires are also a type of corundum, but they derive their blue color from trace amounts of iron and titanium. The most valuable sapphires come from Kashmir, where the combination of geological conditions results in a unique, velvety blue hue. Sapphires are also found in other parts of the world, including Sri Lanka, Thailand, and Australia, but Kashmir sapphires are considered the most desirable and expensive.
Tanzanite, a relatively modern discovery, was first found in Tanzania in 1967. It is a type of zoisite that has been treated to enhance its color. The fact that tanzanite is only found in a specific region of Tanzania makes it extremely rare, contributing to its high value. Despite being a relatively new gemstone, it has quickly gained popularity and is now one of the most expensive birthstones.
Diamonds, while not the rarest gemstones, are highly valued due to their global demand and the marketing strategies of the jewelry industry. The most expensive diamonds are those with large carat weights, high clarity, and rare colors such as pink, blue, or green. These stones are typically found in a few key regions, including South Africa, Australia, and Canada.
Gemological Properties
The gemological properties of the most expensive birthstones play a crucial role in determining their value. These properties include color, clarity, cut, carat weight, and hardness on the Mohs scale.
Alexandrite is known for its color-changing properties, which make it highly desirable. On the Mohs scale, it ranks at 8.5, making it quite durable. Its refractive index ranges from 1.74 to 1.78, and its chemical composition is Al₂BeO₄. The rarity of large, high-quality alexandrite stones contributes to its high price.
Rubies have a hardness of 9 on the Mohs scale, making them one of the hardest gemstones after diamonds. Their refractive index is between 1.76 and 1.78. The most valuable rubies have a deep red color, often described as "pigeon blood," and a high degree of clarity. Large, high-quality rubies are extremely rare, which drives up their price.
Sapphires also rank at 9 on the Mohs scale, and their refractive index is between 1.76 and 1.78. The most valuable sapphires have a deep blue color and high clarity. Kashmir sapphires, in particular, are known for their unique color and are among the most expensive sapphires on the market.
Tanzanite has a hardness of 6-6.5 on the Mohs scale, which means it is relatively soft compared to other gemstones. It is often used in display pieces rather than in jewelry due to its fragility. Its refractive index is between 1.69 and 1.70, and its chemical composition is CaAl₃(SiO₄)(OH)₃. The fact that it is only found in Tanzania makes it highly valuable.
Diamonds, with a hardness of 10 on the Mohs scale, are the hardest naturally occurring substance on Earth. Their refractive index is between 2.417 and 2.419, which gives them their characteristic brilliance. The most valuable diamonds are those with high clarity, large carat weights, and rare colors.
Symbolism and Metaphysical Beliefs
Throughout history, gemstones have been associated with various symbolic and metaphysical properties. These beliefs have influenced the value and popularity of certain birthstones.
Alexandrite is often associated with transformation and adaptability. Its ability to change color is seen as a metaphor for personal growth and change. In Russian folklore, it was believed that alexandrite could bring good fortune and protect the wearer from harm. In modern times, it is considered a symbol of courage and resilience.
Rubies have long been associated with passion, vitality, and protection. In ancient times, they were believed to promote longevity and ward off evil. In medieval Europe, they were thought to bring wisdom and virtue. Today, rubies are still associated with love and passion, making them a popular choice for engagement rings and other romantic gifts.
Sapphires are often associated with wisdom, clarity, and spiritual insight. In medieval Europe, they were believed to promote truth and purity. The deep blue color of sapphires has also been linked to the heavens and the divine. In modern times, sapphires are often used in jewelry to symbolize loyalty and devotion.
Tanzanite is a relatively new gemstone, but it has quickly gained popularity in the world of metaphysics. It is often associated with transformation and emotional healing. Its connection to the month of December makes it a popular choice for those seeking to embrace change and new beginnings.
Diamonds have long been associated with love, commitment, and eternity. Their hardness and durability make them a symbol of enduring love and strength. In modern times, diamonds are most commonly associated with engagement rings and wedding jewelry.
Care and Cleaning
Due to their high value, proper care and cleaning are essential for preserving the beauty and integrity of expensive birthstones. Each gemstone has specific requirements based on its hardness, chemical composition, and sensitivity to heat and light.
Alexandrite, with a hardness of 8.5, is relatively durable and can be cleaned with warm, soapy water and a soft brush. It is important to avoid exposure to high heat, as this can cause it to lose its color-changing properties.
Rubies, with a hardness of 9, are also quite durable. They can be cleaned with warm, soapy water and a soft cloth. However, it is important to avoid exposure to harsh chemicals, as this can damage the gemstone's surface.
Sapphires, also with a hardness of 9, are similarly durable. They can be cleaned with warm, soapy water and a soft brush. However, it is important to avoid exposing them to high heat, as this can cause them to lose their color.
Tanzanite, with a hardness of 6-6.5, is relatively soft and requires more careful handling. It should be cleaned with a soft cloth and mild soap, and it is important to avoid exposure to high heat or direct sunlight, as this can cause it to fade.
Diamonds, with a hardness of 10, are the most durable of all gemstones. They can be cleaned with warm, soapy water and a soft brush or a diamond-specific cleaning solution. However, it is important to avoid using harsh chemicals or abrasive materials, as this can damage the gemstone's surface.
Conclusion
The most expensive birthstones are not only prized for their beauty but also for their rarity, historical significance, and unique gemological properties. From the color-changing alexandrite to the deep red ruby and the velvety blue sapphire, each of these gemstones tells a story of natural wonder and human fascination. Understanding the factors that contribute to their high value—such as color, clarity, carat weight, and origin—can help collectors and enthusiasts appreciate these stones on a deeper level. Whether as an investment, a meaningful gift, or a personal treasure, these rare and valuable birthstones continue to captivate and inspire.