July is the only month with two officially recognized birthstones: ruby and onyx. These gemstones have captivated cultures for centuries with their beauty, symbolism, and enduring significance. This article explores the rich history, gemological properties, cultural meanings, and practical considerations of both ruby and onyx, drawing on authoritative sources to provide an in-depth understanding of these July birthstones.
Historical Significance and Lore
Ruby: The King of Gemstones
Ruby, the most widely recognized of the two July birthstones, has a history as vibrant as its color. Ancient civilizations revered ruby not only for its beauty but also for its perceived mystical properties. In ancient India, ruby was known as the "king of precious stones," a title that reflected its rarity and the belief in its mystical powers. It was associated with the life force of blood and considered a symbol of power and youthful energy.
Historically, ruby was also believed to possess prophetic abilities. Some cultures held that the stone could predict misfortune or danger—its color would deepen before a catastrophe occurred. In Burmese tradition, warriors carried rubies into battle, believing the stones made them invincible. Medieval Europeans associated ruby with health, wisdom, wealth, and success in love, reinforcing its status as a gemstone of immense value.
Ruby's historical significance is further underscored by its presence in royal regalia. Crowns, scepters, and other symbols of monarchy frequently featured rubies, often as a representation of good fortune and divine favor.
Onyx: The Stone of Strength and Protection
While ruby is often the more celebrated of the two July birthstones, onyx has its own rich historical legacy. Onyx has been used in jewelry and decorative arts for thousands of years, appearing in artifacts from ancient Egypt, Greece, and Rome. In ancient Greece and Rome, onyx was prized not only for its aesthetic appeal but also for its supposed protective qualities. It was believed to offer protection from negative energy and misfortune, making it a popular stone for warriors and travelers.
Onyx was also used in amulets and seals, particularly in the ancient world, where it was engraved with intricate designs and inscriptions. In medieval Europe, onyx was associated with strength and self-discipline, often worn by those seeking to overcome challenges or maintain composure under pressure.
Though less commonly referenced in the modern birthstone tradition, onyx has retained its allure and continues to be appreciated for its durable, elegant appearance.
Geological Formation and Sources
Ruby: A Product of Tectonic Forces
Ruby is a variety of the mineral corundum, which is composed of aluminum oxide (Al₂O₃). The intense red color of ruby is caused by trace amounts of chromium, which substitutes for some of the aluminum in the crystal structure. The more chromium present, the deeper the red hue.
The formation of ruby is closely tied to tectonic activity. According to geological research, many ruby deposits formed during continental collisions that occurred millions of years ago. These geological events created the high-pressure and high-temperature conditions necessary for ruby to crystallize.
Today, ruby is found in a number of locations around the world. Burmese rubies, particularly those from the Mogok region, are considered some of the finest in the world. Other notable sources include Sri Lanka, Thailand, Tanzania, and Madagascar. Each location produces rubies with slightly different characteristics, influenced by the local geological environment.
Onyx: A Form of Chalcedony
Onyx is a type of chalcedony, a microcrystalline form of silica (SiO₂). It is typically characterized by parallel bands of color, most commonly in black and white, though it can also appear in other color combinations such as red and white or grey and white.
Onyx forms in sedimentary environments, where layers of silica-rich material gradually build up and harden over time. The banded appearance is the result of alternating layers of different-colored silica, often influenced by impurities or mineral inclusions.
Historically, Brazil has been one of the largest producers of onyx. Other significant sources include India, Uruguay, and the United States. Unlike ruby, onyx is relatively abundant and accessible, contributing to its enduring popularity in jewelry and decorative objects.
Gemological Properties
Ruby: A Hard and Radiant Gem
Ruby is one of the hardest gemstones, with a Mohs hardness of 9, second only to diamond. This makes it highly durable and suitable for everyday wear. However, ruby can have inclusions or internal fractures, which can affect its toughness. Proper care is necessary to prevent damage, especially in rings or other frequently worn jewelry.
The finest rubies are those with a deep red color and a slight purple undertone, a hue known in the trade as "pigeon's blood." This term refers to the most valuable and visually striking rubies, particularly those from Burma.
Ruby has a refractive index ranging from 1.76 to 1.78, and its specific gravity is approximately 4.00. These properties help gemologists identify ruby and distinguish it from other red gemstones such as garnet or spinel.
Onyx: A Durable and Versatile Stone
Onyx has a Mohs hardness of 6.5 to 7, making it more durable than many other semi-precious stones but less so than ruby. It is relatively tough and resistant to breaking, though it can be scratched by harder materials. Onyx does not have cleavage, which means it is less likely to split along natural lines.
The refractive index of onyx is around 1.48 to 1.53, and its specific gravity is approximately 2.60. These properties make onyx easy to identify and distinguish from other banded stones such as agate or tiger's eye.
Onyx is also polishable, which allows it to achieve a high luster. This characteristic makes it ideal for carvings, beads, and cabochons, and it is often used in engraved seals and intaglios.
Symbolism and Metaphysical Beliefs
Ruby: A Symbol of Love and Power
Ruby has long been associated with passion, love, and vitality. In many cultures, it is considered a stone of the heart, believed to enhance emotional warmth and romantic energy. Ancient texts describe ruby as a source of life force and vitality, and it was often worn to boost courage and confidence.
In medieval Europe, ruby was thought to bring good fortune and success in love, making it a popular choice for engagement rings and romantic gifts. It was also believed to ward off illness and negative influences, and some cultures used ruby as a protective amulet.
Modern metaphysical practitioners continue to associate ruby with emotional healing and inner strength. It is believed to stimulate the heart chakra, promoting love, compassion, and emotional balance.
Onyx: A Stone of Strength and Protection
Onyx is often regarded as a stone of grounding and protection. In ancient times, it was believed to shield the wearer from negative energy and misfortune, making it a favored stone for warriors and travelers. Onyx was also associated with self-discipline and emotional stability, helping individuals maintain focus and composure in challenging situations.
In modern metaphysical beliefs, onyx is used to absorb negative energy and promote emotional balance. It is particularly valued for its ability to enhance willpower and determination, making it a popular stone for those seeking to overcome obstacles or achieve personal goals.
Onyx is also associated with the root chakra, symbolizing stability, security, and connection to the earth. It is often used in jewelry and meditation practices to support emotional grounding and inner strength.
Care and Cleaning
Ruby: Maintenance and Durability
Given its high hardness, ruby is a very durable gemstone. However, it can still be damaged by harsh chemicals or impact, so proper care is essential. To clean ruby jewelry, use mild soap and warm water, along with a soft-bristled brush. Avoid using ultrasonic cleaners, as they can potentially damage certain inclusions or fracture the stone.
Ruby is also sensitive to heat and sudden temperature changes, so it should be stored separately from other jewelry to prevent scratches or abrasions. When not in use, ruby should be kept in a soft cloth or padded jewelry box.
Onyx: Easy to Care for and Maintain
Onyx is relatively easy to care for, though it is more porous than ruby and can be damaged by harsh chemicals or abrasive cleaners. To clean onyx jewelry, use mild soap and warm water, and avoid soaking it for long periods to prevent water absorption.
Onyx can also be damaged by exposure to acidic substances, so it is best to remove onyx jewelry before using household cleaners or lotions. When storing onyx, keep it in a dry, cool place, away from direct sunlight or other gemstones that might scratch it.
Conclusion
July's two birthstones—ruby and onyx—each offer a unique combination of beauty, history, and symbolism. Ruby, with its deep red hue and centuries-old legacy, continues to be a symbol of love, power, and vitality. Onyx, with its durable, banded appearance, has long been valued for its protective and grounding properties.
Whether you choose ruby for its radiant brilliance or onyx for its soothing presence, both gemstones are rich in meaning and cultural significance. Understanding their geological properties, historical background, and practical care requirements can help you make an informed and meaningful choice when selecting a July birthstone.