The Official Birthstone Chart: A Guide to Gemstones by Month

A birthstone chart serves as a definitive visual guide, assigning specific precious and semi-precious gemstones to each month of the year. These charts are more than just a reference for jewelry; they represent a convergence of ancient history, cultural tradition, and modern gemological standards. For centuries, individuals have looked to these stones not only for their aesthetic beauty but also for the deep symbolic meanings and protective qualities they are believed to hold. From the deep red of January's garnet to the vibrant blue of December's tanzanite, each gemstone tells a story of geological formation, historical significance, and personal identity. This article explores the comprehensive world of birthstone charts, detailing the official and traditional stones, their evolution, and the essential properties that make them treasured across the globe.

The concept of a standardized birthstone chart is a relatively modern invention, yet its roots stretch back to ancient civilizations. The most influential precursor to today's charts is the Breastplate of Aaron, a sacred artifact described in the biblical Book of Exodus. This vestment was adorned with twelve distinct gemstones, each representing one of the twelve tribes of Israel. This ancient practice of assigning specific stones to groups of people laid the groundwork for the later association of gemstones with calendar months. Over time, these associations evolved, influenced by various cultural and astrological traditions, including Polish, Italian, Arabic, and Hebrew charts, as well as those based on zodiac signs. Today, the most widely recognized system is the official birthstone chart established in the United States, which has been amended over the years to reflect changing tastes and the availability of new gemstones. This chart, along with lists of traditional and alternative stones, provides a rich tapestry of options for those seeking a personal connection to the mineral kingdom.

History and Lore

The journey from ancient talismans to a standardized modern chart is a fascinating one. The earliest and most significant historical reference is the Breastplate of Aaron, which established a precedent for linking gemstones with specific groups. While the exact identification of the stones on the breastplate is a subject of scholarly debate, the principle of twelve stones for twelve tribes was a powerful symbolic concept. This tradition was later adopted and adapted by various cultures, leading to a multitude of birthstone lists based on different criteria, such as the month of the Hebrew calendar or the Julian calendar.

The modern, standardized system began to take shape in 1912 when the American National Retail Jewelers Association (now Jewelers of America) convened to create an official list. This was a significant step in creating a unified standard for the jewelry trade in the United States. The goal was to select stones that were commercially available, durable enough for everyday wear in jewelry, and aesthetically appealing. The 1912 list established the foundation for today's chart, with a few notable exceptions. For instance, June was assigned pearl as its primary stone, a choice that would later be amended.

The official chart has been updated several times to remain relevant. A 1952 amendment added Alexandrite to June and Spinel to August, acknowledging the growing popularity and availability of these gems. In 2002, Tanzanite was added as an official option for December, and in 2016, Spinel was officially added as a modern birthstone for August, alongside Peridot. These amendments demonstrate that the birthstone chart is not a static relic but a living document that evolves with the gemstone market and consumer preferences. Alongside the official list, traditional birthstones, such as Bloodstone for March and Opal for October, continue to hold cultural significance and remain popular choices, often for their historical resonance or lower cost.

The Official and Traditional Birthstone Charts

The official birthstone chart for the United States is the most commonly referenced list in the Western world. It provides a primary "modern" stone for each month, with some months offering additional official options. This chart is the result of careful selection by a trade organization to provide a reliable standard for jewelers and consumers.

In contrast, traditional birthstone charts draw from a deeper well of history and cultural practice. These lists often include stones that were associated with a given month long before the 1912 standardization. For many people, traditional stones offer a more authentic or historical connection. The modern chart is often preferred for its use of readily available, durable, and consistently colored gems suitable for contemporary jewelry design. However, the two lists are frequently used interchangeably, and many jewelers offer pieces featuring both modern and traditional options, allowing for a high degree of personalization.

The following table, compiled from information across multiple authoritative sources, provides a comprehensive overview of the modern, traditional, and alternative birthstones for each month, along with their key symbolic meanings and general hardness ratings on the Mohs scale.

This table illustrates the diversity within the birthstone system. For months like June and December, there is a wide array of choices, ranging from the organic pearl to the brilliant blue of tanzanite. The symbolism associated with each stone also provides a layer of meaning that enhances its value as a gift, transforming a piece of jewelry into a talisman of specific virtues, such as the courage of aquamarine or the wisdom of sapphire.

Gemological Properties and Characteristics

Understanding the physical properties of birthstones is crucial for both jewelers and consumers. These properties determine a gem's durability, appearance, and care requirements. The most critical property is hardness, measured on the Mohs scale, which indicates a mineral's resistance to scratching. For example, April's diamond, with a perfect Mohs rating of 10, is the hardest known natural material, making it exceptionally durable for daily wear. In contrast, June's traditional birthstone, pearl, has a very low hardness (2.5-4.5) and is an organic gem, making it much more susceptible to damage from acids, abrasion, and impacts.

Color is another defining characteristic. While many people associate a specific color with a birthstone, the range within a single gem species can be vast. Garnet, the birthstone for January, is a prime example. While most commonly known for its deep red hues, garnets occur in a stunning variety of colors, including vibrant greens, oranges, and even rare blues discovered in the 1990s. This diversity allows for a wide range of jewelry styles, from classic red rings to modern, colorful pieces. Similarly, tourmaline, an option for October, is famously known as the "rainbow gemstone" for its ability to appear in virtually every color of the spectrum.

Clarity and cut also play a significant role in a gem's beauty and value. Many birthstones, like diamond, sapphire, and ruby, are expected to be transparent and relatively inclusion-free to command the highest prices. Others, like opal, are prized for their internal patterns and "play-of-color," a phenomenon where flashes of iridescent light move across the stone's surface. The cut of a gemstone is an art form designed to maximize its optical properties, such as brilliance and fire. A well-cut amethyst will showcase its rich purple color and sparkle, while a skilled lapidary can bring out the best in a peridot's lively green hue.

Geological Formation and Sources

Each birthstone has a unique origin story, formed under specific geological conditions deep within the Earth. These conditions determine the chemical composition, color, and crystal structure of each gem.

• January (Garnet): Garnets are a group of silicate minerals that form in metamorphic rocks. They are found in a wide range of locations globally, including the United States (Idaho, Arizona), Sri Lanka, India, and Africa.
• February (Amethyst): A variety of quartz, amethyst forms in geodes and volcanic rocks. Major sources include Brazil, Uruguay, and Zambia. Its purple color is caused by iron impurities and natural irradiation.
• March (Aquamarine): A member of the beryl family (which also includes emerald), aquamarine forms in igneous and metamorphic rocks. Its signature blue-to-blue-green color comes from iron impurities. Brazil, Nigeria, and Madagascar are key sources.
• April (Diamond): Diamonds are formed of pure carbon under immense pressure and temperature deep in the Earth's mantle. They are brought to the surface through volcanic activity. Major mining locations include Botswana, Russia, Canada, and Australia.
• May (Emerald): Also a beryl, emerald gets its vibrant green from trace amounts of chromium and vanadium. It typically forms in hydrothermal veins. Colombia, Zambia, and Brazil are renowned for producing the world's finest emeralds.
• June (Pearl & Alexandrite): Pearls are organic gems created inside mollusks. Cultured pearls now dominate the market, with major sources in Japan, China, and Australia. Alexandrite is a variety of chrysoberyl that exhibits a dramatic color change from green in daylight to red in incandescent light. It was famously discovered in Russia's Ural Mountains, but new sources have been found in Brazil, Sri Lanka, and East Africa.
• July (Ruby): A variety of the mineral corundum, ruby is one of the hardest gemstones (Mohs 9). Its coveted red color is due to the presence of chromium. The most prized rubies come from Myanmar (Burma), with other significant sources in Thailand, Mozambique, and Vietnam.
• August (Peridot & Spinel): Peridot is the gem-quality variety of olivine, a mineral formed deep in the Earth's mantle and brought to the surface by volcanoes. It is found in places like Arizona, Pakistan, and Myanmar. Spinel forms in the same metamorphic rocks as ruby and has historically been mistaken for it. Major sources include Myanmar, Sri Lanka, and Thailand.
• September (Sapphire): Another corundum variety, sapphire is most famous for its blue hue, caused by iron and titanium impurities. While blue is the classic color, sapphire occurs in a rainbow of shades (known as "fancy sapphires"). Key sources include Sri Lanka, Kashmir (India), and Myanmar.
• October (Opal & Tourmaline): Opal is a non-crystalline silica gem known for its unique play-of-color. Australia is the dominant source, producing over 90% of the world's opals. Tourmaline is a complex borosilicate mineral that forms in pegmatites. Its wide color range means it is sourced from many locations, including Brazil, Afghanistan, and Africa.
• November (Topaz & Citrine): Topaz is a fluorosilicate mineral that comes in a variety of colors, with blue and golden yellow being popular. Brazil is a major source. Citrine is a variety of quartz with a yellow-to-orange color, sourced largely from Brazil.
• December (Tanzanite, Zircon & Blue Topaz): Tanzanite is a relatively recent discovery (1967) found in only one location in the world: the Merelani Hills of Tanzania. Blue zircon is the modern blue birthstone for December, distinct from the cubic zirconia man-made simulant. Blue topaz, another December option, is often colorless quartz that is irradiated and heated to achieve its blue hue.

Symbolism and Metaphysical Beliefs

Beyond their physical beauty, birthstones are deeply embedded in the world of symbolism and metaphysical lore. For thousands of years, people have attributed special powers and meanings to these gems, believing they could influence health, fortune, and emotional well-being. While these beliefs are not scientifically proven, they form an integral part of the cultural significance of birthstones and enhance their appeal as meaningful gifts.

• Garnet (January): Believed to be a stone of constancy, it symbolizes friendship and trust and is thought to provide protection during travel.
• Amethyst (February): Known for its calming energy, amethyst is associated with peace, sincerity, and the prevention of overindulgence.
• Aquamarine (March): As a stone of the sea, it has long been a talisman for sailors, believed to ensure safe passage and bring courage, wisdom, and clarity of thought.
• Diamond (April): A symbol of eternal love and innocence, diamond is believed to amplify positive energies and bring strength and clarity to the wearer's mind.
• Emerald (May): A stone of successful love, emerald is associated with rebirth, fertility, and wisdom. It is thought to bring domestic bliss and vitality.
• June (Pearl & Alexandrite): Pearls symbolize purity, innocence, and faith. Alexandrite is known as a stone of good omens, believed to bring joy, luck, and intuition.
• Ruby (July): A stone of passion and prosperity, ruby is believed to stimulate the heart chakra, encourage活力, and protect against negative energy.
• August (Peridot & Spinel): Peridot is a stone of strength and good fortune, believed to ward off evil spirits and bring peace to relationships. Spinel is associated with revitalizing energy and renewed commitment.
• September (Sapphire): A symbol of wisdom, truth, and loyalty, sapphire is believed to bring mental clarity, focus, and spiritual enlightenment.
• October (Opal & Tourmaline): Opal is a stone of hope, creativity, and innocence, thought to inspire originality and amplify emotions. Tourmaline is known as a protective stone, believed to repel and block negative energy.
• November (Topaz & Citrine): Topaz symbolizes love and affection and is thought to aid in stress relief and tissue repair. Citrine, known as the "merchant's stone," is believed to attract wealth, prosperity, and success.
• December (Tanzanite, Zircon & Blue Topaz): These blue stones are associated with wisdom, serenity, and good fortune. Tanzanite is believed to facilitate a higher consciousness and spiritual awakening, while turquoise (a traditional December stone) is one of the oldest protective talismans.

Care and Cleaning

Proper care is essential to maintain the beauty and longevity of birthstone jewelry. The diverse physical properties of these gems dictate specific cleaning and handling methods. A one-size-fits-all approach can lead to damage, particularly for softer or more porous stones.

• Hard Stones (Mohs 7 and above): This group includes diamond, sapphire, ruby, aquamarine, topaz, and citrine. These gems are quite durable and can be safely cleaned with warm water, a small amount of mild dish soap, and a soft brush (like a baby toothbrush). They can also be taken for professional steam cleaning.
• Medium-Hard Stones (Mohs 6.5 - 7): This includes garnet, peridot, amethyst, and tanzanite. While still relatively durable, they are more susceptible to damage than the harder stones. Warm soapy water and a soft brush are safe, but ultrasonic cleaners should be used with caution, if at all, especially for peridot and tanzanite, which can have inclusions or fractures.
• Softer or Porous Stones (Below Mohs 7): This is a critical category that requires special attention.
  • Pearl (Mohs 2.5-4.5): Pearls are extremely delicate. They should be wiped with a soft, damp cloth after each wear. They should never be submerged in water or exposed to chemicals, including perfume, hairspray, and cosmetics, which can damage their luster.
  • Opal (Mohs 5.5-6.5): Opals are sensitive to temperature changes and can crack if they dry out ("crazing"). Clean them gently with a soft, damp cloth. Avoid ultrasonic cleaners, steam, and harsh chemicals.
  • Emerald (Mohs 7.5-8): Although hard, most emeralds contain significant internal inclusions and fractures. They are often treated with oil or resin to improve their appearance. Ultrasonic cleaners and harsh chemicals can remove these fillings and damage the stone. Use only mild soapy water and a soft brush.
  • Turquoise (Mohs 5-6): As a porous stone, turquoise can be damaged by chemicals, lotions, and even the oils from skin contact. Clean with a soft, dry cloth.

When in doubt, it is always safest to use the mildest cleaning method—warm water and a soft cloth—and to consult a professional jeweler for advice on cleaning and maintaining valuable or delicate pieces.

Conclusion

The birthstone chart is a powerful and enduring cultural artifact. It bridges the ancient world of the High Priest's breastplate with the modern jewelry counter, offering a personalized connection to the Earth's geological wonders. From the standardized official list to the rich variety of traditional and alternative stones, the chart provides a diverse palette of gems, each with unique properties, historical significance, and symbolic meaning. Understanding the gemological characteristics, from the exceptional hardness of the diamond to the organic delicacy of the pearl, is key to appreciating and caring for these treasures. Whether chosen for their beauty, durability, or the lore of protection and prosperity they are said to bestow, birthstones remain a cherished tradition, transforming a simple mineral into a deeply personal emblem of identity and a timeless piece of art.

Sources

1. mybirthstone.org
2. jewelryinformer.com
3. monthlybirthstones.com
4. gemsociety.org
5. birthstones.guru