A birthstone chart serves as a definitive visual reference, linking specific gemstones to each calendar month. These charts are more than mere lists; they are gateways to centuries of cultural tradition, geological wonder, and personal significance. The practice of assigning a gemstone to one's birth month has evolved over time, with modern charts often reflecting a blend of historical tradition and contemporary preferences. This article provides a detailed exploration of the birthstones for each month, drawing from authoritative sources to present their history, properties, and symbolism. It is designed for gemstone enthusiasts, jewelry buyers, and students of gemology seeking an in-depth understanding of these celebrated minerals.
The concept of birthstones is rooted in ancient traditions, notably the twelve stones on the breastplate of the High Priest in the Old Testament. While interpretations varied across cultures and eras, a standardized modern list was established in 1912 by the National Association of Jewelers in the United States, with subsequent amendments in 1952, 2002, and 2016. Today, many months offer both a traditional and a modern birthstone, allowing for personal choice based on color, symbolism, or budget. This guide will navigate the primary gemstones for each month, detailing their unique characteristics and the lore that surrounds them.
January: Garnet
Garnet is the traditional and modern birthstone for January. It is a silicate mineral group comprising several related species of lustrous gemstones, ranging from transparent to opaque. Garnet possesses a reasonably tough Mohs hardness rating of around 7, making it durable for everyday jewelry.
While the most common color for garnet is red, these gemstones can be found in almost any color. Blue garnets, the rarest variety, were discovered in the 1990s. Most garnet species are not rare, which contributes to its accessibility in the market. The symbolic meaning associated with garnet is constancy, representing loyalty and enduring friendship.
February: Amethyst
Amethyst is the birthstone for February, recognized for both its traditional and modern listings. It is a variety of quartz, valued for its distinctive purple hue. The symbolic meaning attributed to amethyst is sincerity.
Amethyst's color, which can range from light lavender to deep violet, has made it a popular choice for jewelry throughout history. As a member of the quartz family, it shares the hardness and durability typical of its mineral group, though specific gemological properties beyond its color and meaning are not detailed in the provided materials.
March: Aquamarine and Bloodstone
March offers a choice between a modern and a traditional birthstone. The modern birthstone is aquamarine, while the traditional stone is bloodstone.
Aquamarine is a variety of the mineral beryl, known for its captivating blue to blue-green hues, reminiscent of seawater. Its name derives from the Latin for "sea water." Aquamarine is associated with the meaning of wisdom. As a beryl, it shares the gemological family with emeralds and morganite, though the sources do not specify its hardness or other properties for this article.
Bloodstone, the traditional birthstone for March, is a dark green chalcedony (a variety of quartz) characterized by red inclusions of iron oxide or jasper, which resemble drops of blood. While its specific properties are not detailed in the provided materials, it has a long history of use in amulets and signet rings.
April: Diamond
Diamond is the undisputed birthstone for April, serving as both the traditional and modern choice. It is the only gem composed of a single element: carbon, arranged in a cubic crystal structure. Diamond is renowned for its exceptional hardness, rating a 10 on the Mohs scale, making it the hardest known natural material.
The symbolic meaning of diamond is innocence. Its unparalleled brilliance and fire have made it the ultimate symbol of love and commitment, particularly in engagement rings. While the sources confirm its status and meaning, detailed gemological data such as refractive index or specific mining locations are not provided in this context.
May: Emerald
Emerald is the birthstone for May, recognized as both traditional and modern. It is a variety of the mineral beryl, prized for its vivid green color. The most prized emeralds exhibit a deep, saturated green with a slightly bluish undertone.
Emerald is associated with the meaning of happiness. Its color is due to trace amounts of chromium and sometimes vanadium. Emeralds are known for their characteristic inclusions, often referred to as "jardin" (French for garden), which are accepted as part of the stone's identity. The sources provided do not specify the chemical formula or hardness, but as a beryl, it typically ranges from 7.5 to 8 on the Mohs scale.
June: Pearl and Alexandrite
June is unique in having two official birthstones: pearl (traditional) and alexandrite (modern). Both are associated with the meaning of wealth.
Pearl is an organic gemstone, formed within the soft tissue of a living mollusk. Unlike mineral gemstones, pearls are not mined from the earth. They are composed primarily of calcium carbonate in the form of aragonite or calcite, layered with conchiolin. Pearls are relatively soft, with a Mohs hardness of 2.5 to 4.5, and require careful handling. Natural pearls are rare and valuable, while cultured pearls make up the majority of the market.
Alexandrite is a variety of the mineral chrysoberyl, famous for its dramatic color change—appearing green in daylight and red or purplish-red in incandescent light. This phenomenon is due to the specific way the stone absorbs light. Alexandrite is a relatively hard gemstone, with a Mohs hardness of 8.5, making it suitable for jewelry. Its discovery in the Ural Mountains of Russia in the 1830s is a well-known historical event, though the exact date is not specified in the provided materials.
July: Ruby
Ruby is the birthstone for July, holding both traditional and modern status. It is a variety of the mineral corundum (aluminum oxide), with its red color derived from trace amounts of chromium. The most prized rubies exhibit a vivid, pure red with a slightly purplish hue, often described as "pigeon's blood."
Ruby is associated with the meaning of freedom. It is one of the four precious gemstones (along with diamond, emerald, and sapphire) and is highly valued for its rarity and color. Corundum has a Mohs hardness of 9, making ruby an exceptionally durable gemstone for jewelry. The sources do not specify mining locations or other gemological details beyond its color and hardness.
August: Peridot and Spinel
August offers two modern birthstones: peridot (the primary stone) and spinel. The traditional birthstone for August is sardonyx. Peridot is associated with the meaning of friendship.
Peridot is the gem variety of the mineral olivine, with the chemical formula (Mg, Fe)₂SiO₄. Its distinctive olive-green color is due to its iron content. Peridot is one of the few gemstones that occur in only one color, though the shade can vary from yellow-green to brownish-green. It has a Mohs hardness of 6.5 to 7, making it moderately durable. Peridot is found in volcanic rock and in meteorites.
Spinel is a separate mineral group, often confused with ruby throughout history. It occurs in a wide range of colors, including red, pink, blue, and black. Red spinel, in particular, has been mistaken for ruby. Spinel has a Mohs hardness of 8, making it a durable gemstone. The sources provided do not detail specific properties or origins for either peridot or spinel.
September: Sapphire
Sapphire is the birthstone for September, recognized as both traditional and modern. It is a variety of corundum (aluminum oxide), like ruby, but its color comes from trace elements such as iron, titanium, and chromium. While sapphire is most famously blue, it can occur in many colors, with the exception of red (which is classified as ruby). The term "sapphire" alone typically refers to the blue variety.
Sapphire is associated with the meaning of truth. It has a Mohs hardness of 9, making it extremely durable and suitable for all types of jewelry. The sources do not specify the exact shades of blue or other gemological data.
October: Tourmaline and Opal
October provides two birthstones: tourmaline (modern) and opal (traditional). Both are associated with the meaning of hope.
Tourmaline is a complex borosilicate mineral with a wide range of chemical compositions, resulting in a vast array of colors. It is often called the "rainbow gemstone." Tourmaline can be found in every color, and some specimens display multiple colors in a single crystal. It has a Mohs hardness of 7 to 7.5, making it reasonably durable. The sources do not specify which variety of tourmaline is most commonly used as a birthstone.
Opal is an amorphous form of silica (hydrated silicon dioxide), containing water within its structure. It is renowned for its play-of-color, an optical phenomenon where flashes of rainbow colors appear as the stone is moved. Opal is relatively soft, with a Mohs hardness of 5 to 6.5, and is sensitive to heat and sudden temperature changes. It requires careful care to prevent cracking or crazing.
November: Topaz and Citrine
November offers two modern birthstones: golden topaz (also called imperial topaz) and citrine. The traditional birthstone for November is topaz. Both are associated with the meaning of loyalty.
Topaz is a silicate mineral of aluminum and fluorine. The most valued topaz is the imperial topaz, which exhibits a rich golden-orange to pinkish-orange color. Topaz has a Mohs hardness of 8, making it a durable gemstone. However, it has perfect cleavage in one direction, meaning it can be split with a sharp blow, requiring careful setting in jewelry.
Citrine is a variety of quartz, known for its yellow to brownish-orange color. Its color is due to trace amounts of iron. Citrine is relatively affordable and has a Mohs hardness of 7, making it durable for everyday wear. It is sometimes called the "merchant's stone" for its association with prosperity.
December: Tanzanite, Turquoise, and Zircon
December has the most birthstones of any month, with three modern options: tanzanite, turquoise, and zircon (blue zircon). The traditional birthstones are turquoise and lapis lazuli. All are associated with the meaning of success.
Turquoise is an opaque, blue-to-green mineral, a hydrated phosphate of copper and aluminum. It has been used for millennia in jewelry and ornaments. Turquoise is relatively soft, with a Mohs hardness of 5 to 6, and is porous, making it susceptible to staining and damage from chemicals. It often forms in veins or nodules in arid regions.
Tanzanite is a variety of the mineral zoisite, discovered in Tanzania in the 1960s. It is prized for its intense violet-blue to blue-violet color, which is often enhanced by heat treatment. Tanzanite has a Mohs hardness of 6.5 to 7, making it moderately durable. It is trichroic, meaning it shows three different colors when viewed from different angles: blue, violet, and burgundy.
Zircon is a silicate mineral (zirconium silicate) that should not be confused with synthetic cubic zirconia. Blue zircon, the variety most commonly used as a birthstone, is typically heat-treated to achieve its blue color. Zircon has a high refractive index and strong dispersion, giving it brilliant fire. It has a Mohs hardness of 7.5, but it can be brittle due to its perfect cleavage.
Conclusion
The birthstone chart is a rich tapestry of geology, history, and symbolism. From the deep red of garnet to the vibrant blue of tanzanite, each month is represented by a gemstone with unique properties and stories. The modern list, standardized in 1912 and updated over time, offers a blend of traditional stones like pearls and opals with modern additions such as spinel and citrine. This diversity allows individuals to choose a gemstone that resonates with them personally, whether based on color, meaning, or budget. Understanding the origins and characteristics of these stones enhances their value, transforming them from simple adornments into meaningful connections to the natural world and cultural heritage.