The month of December boasts a rich selection of birthstones, but among them, onyx stands out as a traditionally significant gem. Characterized by its striking black coloration – though it can also appear in banded black and white varieties – onyx has a long history of use in jewelry and ornamentation. This article will delve into the history, geological origins, gemological properties, symbolism, and care of onyx, focusing on its role as a December birthstone.
History and Lore
Onyx has been utilized for millennia, with archaeological evidence suggesting its use in ancient civilizations. While the provided sources do not detail specific early uses, its durability and aesthetic appeal likely contributed to its popularity in ancient jewelry and carvings. The sources primarily focus on its modern association with December as a birthstone, specifically identifying it as the traditional stone for those born in this month. Sources indicate that December also has modern birthstone options, including blue zircon, blue topaz, and tanzanite, demonstrating a broadening of choices over time. The practice of assigning gemstones to specific months gained prominence in 1912 with the standardization efforts of the National Association of Jewelers, though the tradition itself has older roots.
The sources also briefly touch upon the practice of choosing gemstones based on the day of the week, noting that onyx is associated with Capricorn (December 22-January 20). This connection to astrological signs further illustrates the historical belief in the gemstone’s influence and symbolic power.
Geological Formation and Sources
The provided materials do not offer detailed information regarding the geological formation of onyx. However, they do state that garnets are found throughout the world, with significant U.S. deposits in Idaho and North Carolina. This suggests onyx, like other gemstones, is sourced from various geological locations globally, though specific mining locations are not detailed in the provided texts. The sources do not specify the geological processes involved in onyx formation.
Gemological Properties
Onyx is assessed using the Mohs scale of mineral hardness, a comparative scale from 1 to 10, with diamond ranking as 10 and talc as 1. The sources indicate that most gemstones suitable for jewelry measure 5 or above on this scale. While the exact Mohs hardness of onyx isn’t explicitly stated, its suitability for jewelry suggests it falls within this range.
The defining characteristic of onyx is its color, typically black, but also including banded black and white varieties. The sources mention that black diamonds exist, some of which are treated to achieve their darker shade, and naturally occurring black diamonds are known as carbonados, composed of diamond, graphite, and amorphous carbon. This highlights the range of materials that can produce a black gemstone. The sources do not provide information on the chemical composition, refractive index, or other detailed gemological properties of onyx.
A table summarizing the hardness of common gemstones, based on the provided information, is shown below:
| Gemstone | Mohs Hardness |
|---|---|
| Diamond | 10 |
| Garnet | 7 - 7.5 |
| Amethyst | 7 |
| Onyx | 5+ (implied) |
| Pearl | Not specified, but softer than 5 |
Symbolism and Metaphysical Beliefs
The sources indicate that birthstones hold symbolic meanings that can influence selection. For onyx, the traditional meaning is associated with “faith and fidelity.” The sources also mention that gemstones were believed to absorb the energies of planets and pass them to the wearer, linking them to specific days of the week and astrological signs. For example, wearing a gold topaz on Sunday is believed to harness the Sun’s energy. While the specific metaphysical properties of onyx are not detailed, the broader context suggests a belief in its ability to influence the wearer’s well-being.
The practice of choosing birthstones by color is also highlighted, allowing individuals to select a shade that resonates with them, even if it deviates from the traditional color associated with their birth month. This flexibility acknowledges the personal connection people have with gemstones.
Care and Cleaning
The sources do not provide specific care instructions for onyx. However, given its Mohs hardness of 5 or above, it is likely durable enough for everyday wear. The sources mention that garnets are suitable for everyday wear, suggesting that similarly rated gemstones like onyx would also be appropriate for regular use. General gemstone care practices, such as avoiding harsh chemicals and ultrasonic cleaners, would likely be suitable for onyx.
Beyond Birthstones: Industrial Applications
Interestingly, the sources reveal that gemstones are not solely valued for their aesthetic qualities. They also have practical applications in industrial settings. Diamonds, due to their extreme hardness, are used in cutting tools and drill bits. Garnets, known for their abrasiveness, are used in sandblasting and cutting steel. This demonstrates the versatility of gemstones beyond the realm of jewelry.
The Expanding Birthstone Landscape
The sources highlight the evolving nature of birthstone lists. While a standardized list was created in 1912, additions and modifications have been made over time. Spinel was added as an August birthstone in 2016, and the Jewelry Industry Council of America updated the June and October birthstones in 1952. This ongoing evolution reflects a desire to offer more choices and cater to diverse preferences. The existence of both traditional and modern birthstone lists allows individuals to select the stone that best suits their tastes and beliefs.
Conclusion
Onyx, as the traditional birthstone for December, holds a significant place in the history of gemstones. While the provided sources offer a limited scope of information regarding its geological formation and detailed gemological properties, they clearly establish its historical use, symbolic meaning, and enduring appeal. Its association with faith and fidelity, coupled with its striking black color, makes it a compelling choice for those born in December. The evolving landscape of birthstones, with the addition of modern alternatives, provides individuals with greater flexibility in selecting a gemstone that resonates with their personal preferences. The sources also reveal the broader utility of gemstones, extending beyond adornment to encompass industrial applications, highlighting their remarkable versatility.