For individuals born in July, the calendar offers a unique duality in birthstone choice: the fiery, regal Ruby and the bold, enigmatic Onyx. While Ruby is widely recognized as the primary modern birthstone, Onyx holds a significant historical claim and remains a celebrated alternative. This article delves into the rich histories, geological origins, gemological properties, and cultural symbolism of both stones, providing a comprehensive guide to these two remarkable gemstones that define the seventh month.
History and Lore: A Tale of Two Gems
The tradition of birthstones is ancient, rooted in the belief that gemstones possessed mystical powers linked to specific times of the year. The modern standardized list, however, is a relatively recent development. The distinction between modern and traditional birthstones explains why July claims two gems. Modern birthstones, as officially designated by the Jewelers of America in the 1950s, represent the most commonly recognized gems today. Traditional birthstones, accepted in the early 20th century and earlier, often fell out of favor due to rarity or market availability, leading some months to adopt modern gems that differed from their predecessors.
Ruby, derived from the Latin word “rubeus” meaning “red,” has been celebrated for millennia. In Ancient Sanskrit, it was called “ratnaraj,” or “king of gems,” a title that underscores its esteemed status. Historical accounts describe rubies adorning the crowns of kings and queens, the breastplates of warriors, and the rings of those seeking to amplify energy and courage. Medieval knights believed rubies could deflect arrows, and Renaissance artists ground the stone to depict sacred wounds in religious art. Its fiery red hue, caused by chromium, made it a natural symbol of passion and vitality. By 1912, when the National Association of Jewelers (now Jewelers of America) published its standardized list, Ruby’s regal pedigree and vibrant color cemented its position as July’s primary birthstone.
Onyx, in contrast, carries a legacy of protection and power. As a banded variety of chalcedony, typically black with striking white or contrasting band patterns, Onyx has been used since antiquity for seals, amulets, and jewelry. Mesopotamians carved it into seals to authenticate decrees, Roman generals wore it to channel the ferocity of Mars, and Victorians set it in jet-black rings to honor the departed. Its connection to the zodiac sign Leo, which spans part of July, further ties it to the month. Prior to 1912, Onyx was widely recognized as July’s birthstone across Jewish, Roman, and European traditions. Although officially replaced as the primary gem by Ruby, Onyx remains a valued secondary birthstone, appreciated for its bold aesthetic and historical depth.
Geological Formation and Sources
Understanding the origins of these gems requires a look at their distinct geological pathways.
Ruby: The Corundum Family
Ruby belongs to the corundum mineral family, which also includes sapphires. It is formed under high-pressure and high-temperature conditions within metamorphic rocks. The presence of chromium is what imparts its signature red color; the more chromium, the deeper the red. Rubies are among the rarest gemstones, contributing to their high value. While the provided sources do not specify exact mining locations, they emphasize that rubies command the highest value among colored birthstones due to their rarity and hardness.
Onyx: A Chalcedony Variety
Onyx is a banded variety of chalcedony, a cryptocrystalline form of quartz. It forms in volcanic or sedimentary environments where silica-rich solutions deposit layers, creating the characteristic bands. The most common form is black onyx with white bands, though red varieties known as sardonyx also exist. Like rubies, specific mining locations are not detailed in the sources, but the stone’s historical use across ancient civilizations suggests a long-standing, widespread availability.
Gemological Properties
The physical and chemical properties of Ruby and Onyx differ significantly, influencing their use in jewelry and care requirements.
Ruby
- Chemical Composition: Aluminum oxide (Al₂O₃) with chromium (Cr) as the color-causing impurity.
- Hardness: On the Mohs scale, Ruby is a 9, second only to diamond (10). This exceptional hardness makes it highly durable and resistant to scratching, suitable for everyday wear.
- Crystal System: Trigonal.
- Color: Ranges from vivid red to pinkish red. The sources explicitly state that rubies exist only in shades of red and pink; there are no other colors.
- Clarity: Rubies often contain inclusions. The sources mention that ultrasonic and steam cleaners are generally safe for untreated, heat-treated, and lattice diffusion treated rubies, but caution is advised for fracture-filled or dyed stones.
Onyx
- Chemical Composition: Silicon dioxide (SiO₂), like all quartz varieties.
- Hardness: On the Mohs scale, Onyx is 6.5 to 7, making it durable but less hard than Ruby. It is suitable for jewelry but requires more care to avoid scratches from harder materials.
- Crystal System: Microcrystalline (cryptocrystalline).
- Color: Typically black with contrasting white or colored bands. Red onyx (sardonyx) is also noted.
- Clarity: As a banded stone, clarity is defined by the pattern and contrast of its bands rather than transparency.
Comparative Properties Table
| Property | Ruby | Onyx |
|---|---|---|
| Mineral Family | Corundum | Chalcedony (Quartz) |
| Chemical Formula | Al₂O₃ | SiO₂ |
| Mohs Hardness | 9 | 6.5 - 7 |
| Primary Color | Red to Pink | Black with bands |
| Crystal System | Trigonal | Microcrystalline |
Symbolism and Metaphysical Beliefs
Both stones are steeped in symbolism, reflecting their historical roles and physical characteristics.
Ruby is universally associated with passion, love, energy, and vitality. Its red hue evokes the heart and blood, linking it to courage and life force. In metaphysical traditions, it is believed to heighten awareness, promote success in love and battle, and ward off negative energy. Its regal history as the “king of gems” adds a layer of authority and power to its symbolism.
Onyx embodies protection, strength, and resilience. Its dark color and banded structure are seen as grounding and stabilizing. Historically, it was used as armor and for protective amulets. Metaphysically, it is thought to absorb and transform negative energy, providing emotional stability and focus. Its connection to mourning (as seen in Victorian jewelry) also links it to endurance and the passage of time.
Care and Cleaning
Proper maintenance is essential to preserve the beauty of these gemstones, and their differing properties dictate specific care protocols.
Ruby Care: Due to its exceptional hardness (9 on the Mohs scale), Ruby is highly resistant to scratching and abrasion. It can be cleaned with warm soapy water and a soft brush. For a deeper clean, ultrasonic and steam cleaners are generally safe for untreated, heat-treated, and lattice diffusion treated stones. However, caution is necessary for fracture-filled or cavity-filled rubies, as these treatments can be damaged by harsh cleaning methods. Always consult a professional jeweler if you are unsure of the stone’s treatment.
Onyx Care: With a hardness of 6.5 to 7, Onyx is more susceptible to scratches than Ruby. It should be cleaned with a soft, damp cloth and mild soap. Avoid ultrasonic cleaners and steam, as the vibrations and heat can potentially damage the stone, especially if it has been dyed or treated. Store Onyx jewelry separately from harder gems like diamonds, sapphires, or rubies to prevent scratching.
Conclusion
July’s birthstones offer a compelling choice between two distinct gemstones, each with a profound legacy. Ruby, the modern primary birthstone, is a symbol of passion and regality, prized for its fiery red color and unmatched hardness. Onyx, the traditional alternative, carries a history of protection and power, valued for its bold contrast and symbolic depth. Together, they represent the full spectrum of July’s spirit—from the vibrant zenith of summer to the enduring strength of ancient earth. Whether drawn to the fiery allure of Ruby or the enigmatic elegance of Onyx, those born in July are fortunate to claim two of history’s most significant gems.