Hubbry Logo
JargoonJargoonMain
Open search
Jargoon
Community hub
Jargoon
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Jargoon
Jargoon
Jargoon
View on Wikipedia
from Wikipedia
Zircon (FOV 3.0 × 2.4 mm) from Mont Saint-Hilaire, Canada

Jargoon or jargon (occasionally in old writings jargounce and jacounce) is a name applied by gemologists to zircons that are of sufficient quality to be cut as gemstones, but not the red color that characterizes the hyacinth or jacinth. The word is related to Persian zargun (zircon; zar-gun, "gold-like" or "as gold").[1]

Some of the finest jargoons are green, others brown and yellow, while some are colorless. The colorless jargoon may be obtained by heating certain colored stones. When zircon is heated it sometimes changes color, or loses it, and at the same time usually increases in density and brilliancy. The so-called Matura diamonds, formerly sent from Matara (or Matura) in Sri Lanka, were decolorized zircons.[1]

The zircon has strong refractive power, and its lustre approaches adamantine, but it lacks the fire of diamond. The specific gravity of zircon is subject to variation in different varieties;[dubious – discuss] thus Sir A. H. Church[verification needed] found the specific gravity of a fine leaf-green jargoon to be as low as 3.982, and that of a pure white jargoon as high as 4.705. Jargoon and tourmaline, when cut as gems, are sometimes mistaken for each other, but the specific gravity is distinctive, since tourmaline is only 3.103. Moreover, in tourmaline the dichroism is strongly marked, whereas in jargoon it is feeble. The refractive indices of jargoon are much higher than those of tourmaline.[1]

References

[edit]

Sources

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Jargoon

View on Grokipedia
from Grokipedia
Jargoon, also spelled , is a translucent, colorless to smoky or pale yellowish variety of the mineral (ZrSiO₄), a nesosilicate known for its gemological value when cut and polished. This gem material differs from the more vividly colored variety of zircon, which exhibits orange-red hues, and has been historically distinguished for its subtle tones suitable for jewelry. The term "jargoon" originates from the Old French "," referring to the gem's pale, indistinct appearance compared to more brilliant stones, and it has persisted in gemological literature since at least the . Chemically identical to other zircons, jargoon typically forms as small crystals in igneous rocks such as and , or in metamorphic and sedimentary deposits, often sourced from alluvial gravels in regions like (formerly Ceylon), where colorless specimens were notably abundant. Its refractive index (around 1.81–1.99) and strong double refraction make it suitable for , though it is less common in modern markets due to confusion with synthetic or simulants. Despite its relative obscurity today, jargoon holds historical significance in arts and biblical references to similar stones like "ligure."

Overview

Definition

Jargoon, also known as , is a historical gemological term referring to gem-quality specimens of the that exhibit colorless, pale yellow, or smoky hues, specifically excluding the red-orange variety known as . This designation highlights zircons suitable for use as faceted gemstones due to their transparency and appeal in lighter tones. Unlike , which is a synthetic created in laboratories to mimic diamond's sparkle, jargoon exclusively denotes natural formed through geological processes. The confusion between the two arises from similar names and appearances, but jargoon's natural origin provides it with unique inclusions and optical properties absent in synthetics. In , quality jargoon is evaluated based on criteria such as sufficient clarity—typically eye-clean or better, free from visible inclusions—and adequate size to allow for effective cutting into faceted stones that maximize brilliance and . These attributes ensure the stone's viability for jewelry, emphasizing its role as a distinct variety within the broader family.

Etymology

The term "jargoon" derives from the "jargon," referring to the gem's pale, indistinct appearance compared to more brilliant stones. This linguistic evolution reflects the gem's often golden or yellowish hues, distinguishing it from the red-orange variety known as . During the 18th and 19th centuries, "jargoon" gained prominence in the gem trade and early to specifically denote non-red zircons, particularly those with light or colorless appearances suitable for cutting. French mineralogist René Just Haüy, in his works such as Traité de minéralogie (1801) and later editions, referenced under related terms like "hyacinthe" and "zircone," contributing to the standardization of jargoon as a descriptor for inferior or pale specimens in European texts. Spelling variations between "jargoon" and "jargon" arose historically, with the latter appearing in medieval French sources.

Relation to Zircon

Chemical Composition

Jargoon is a variety of the mineral zircon, with the primary chemical composition of zirconium silicate, expressed by the formula ZrSiO₄. This structure incorporates zirconium (Zr⁴⁺) coordinated with silicon tetrahedra (SiO₄)⁴⁻, forming a stable nesosilicate framework. Trace elements such as hafnium (Hf), which can substitute for zirconium up to several percent, are commonly present and contribute to minor variations in the mineral's properties. Uranium (U) and thorium (Th) also occur as impurities, typically at levels from 100 ppm to 0.1 wt%, influencing both coloration and long-term structural integrity through radioactive decay. The crystal structure of jargoon, like , belongs to the with I4₁/amd. The unit cell parameters are approximately a = 6.607 and c = 5.986 , resulting in a compact arrangement that supports the mineral's high and dispersion. These parameters can vary slightly due to substitutional impurities or radiation-induced damage, but in gem-quality jargoon, they remain close to ideal values, preserving optical clarity. Specific to jargoon, its pale or colorless appearance arises from relatively low concentrations of iron (Fe) and uranium impurities, which in higher amounts produce brownish or reddish hues in other zircon varieties. Iron, when present, typically causes brown coloration by occupying lattice sites, whereas minimal levels allow for the tones characteristic of jargoon. In contrast, the hyacinth variety of exhibits higher uranium content, often zoned within crystals, leading to more intense orange-red colors and greater susceptibility to metamictization. This distinction in impurity levels underscores jargoon's suitability for colorless gem applications.

Gem Varieties

The term "jargoon" is historical and sometimes considered obsolete in strict mineralogical contexts, but in , it refers to gem-quality varieties of characterized by light, subtle hues, specifically colorless, pale yellow, and pale gray specimens suitable for faceting. These varieties are prized for their clarity and brilliance, with the colorless form representing the purest expression of zircon's , often exhibiting high transparency and a diamond-like due to its strong dispersion. The pale yellow variety, sometimes described as straw-like, introduces a faint golden tint that enhances the stone's warmth without overpowering its , while the pale gray or smoky subtype offers a neutral, understated elegance. These colorations arise naturally from trace impurities and structural integrity, though some colorless jargoons can also result from of naturally tinted material. Unlike more saturated zircon varieties—such as the red-brown , or the blue and green types achieved through specific processes—jargoon is reserved exclusively for these low-chroma, near-neutral tones, emphasizing its distinction within the family. Rare subtypes of jargoon include metamict examples, in which long-term from incorporated and disrupts the crystal lattice, altering its physical properties like without necessarily changing the light color. Such metamict jargoons maintain their gem potential but may show reduced and increased opacity if the damage is extensive.

Physical Properties

Optical Characteristics

Jargoon, a transparent to translucent variety of zircon, displays optical properties that provide good light interaction, though low types typical of jargoon exhibit reduced brilliance due to lower refractive indices and possible cloudiness. As a low-type zircon affected by metamictization, jargoon exhibits properties at the lower end of zircon's range. For low forms typical of jargoon, the refractive index is approximately 1.810–1.815 for both ordinary (nω) and extraordinary (nε) rays, contributing to moderate brilliance. This gem's dispersion measures 0.039, producing pronounced in the form of vivid flashes when properly faceted, a trait accentuated by the elevated refractive indices. is low, typically 0.000–0.008, resulting in minimal doubling of facets observable under magnification, which distinguishes it from isotropic gems like . These optical traits are influenced by the degree of metamictization, where radiation-induced damage in low-type jargoon lowers the refractive indices and compared to crystalline high-type , while dispersion remains consistent across varieties. Although specific (3.95–4.20) is a measure rather than strictly optical, it correlates with metamict alterations that indirectly affect light transmission and luster in jargoon. Color variations, such as pale yellow to colorless, can modulate the intensity of these effects, with lighter hues maximizing visibility.

Hardness and Durability

Jargoon, a variety of , exhibits a Mohs ranging from 6 to 7.5, positioning it as moderately for use but requiring careful handling to prevent surface scratches from harder materials like or . This hardness variation arises from structural differences, with high-quality, crystalline specimens approaching 7.5 and metamict (radiation-damaged) forms tending toward the lower end due to partial amorphous transformation. Despite this, jargoon's overall toughness is fair to good, though its brittle tenacity makes it prone to chipping or fracturing under impact, particularly in untreated stones where internal stresses may exist. Jargoon lacks distinct cleavage, displaying only poor or indistinct parting along {110} and {111} planes, which contributes to its resilience against splitting compared to gems with strong cleavage directions. Instead, it typically exhibits a , resulting in smooth, shell-like breaks that can occur if the gem is subjected to sudden blows. Metamict varieties, common in some jargoon sources, show heightened sensitivity to heat and ; prolonged exposure can exacerbate lattice damage, leading to further degradation of mechanical integrity over time. In terms of , jargoon demonstrates strong resistance to most acids and , owing to 's inherent inertness, which protects it from corrosion in typical jewelry environments. However, it is vulnerable to methods, which can cause internal fractures due to the gem's brittleness and potential inclusions; is similarly discouraged. For maintenance, experts recommend avoiding extreme fluctuations to prevent , and instead using warm soapy water with a soft brush for routine cleaning to preserve the stone's durability.

Occurrence and Sourcing

Geological Formation

Jargoon, a variety of characterized by its light coloration, forms primarily through magmatic processes in the . crystals, including those suitable for jargoon, crystallize as accessory minerals in silica-rich s within igneous rocks such as granites and pegmatites. These environments develop during the late stages of cooling, where and silica combine to form ZrSiO₄ under temperatures typically ranging from 700 to 800°C, often over an interval of 80–100°C as the melt evolves. Secondary deposition plays a key role in concentrating gem-quality jargoon-bearing zircons. Erosion of primary igneous sources weathers and transports durable zircon crystals into sedimentary environments, where their high density (specific gravity around 4.6–4.7) causes them to accumulate in placer deposits such as river gravels and beach sands. This mechanical concentration process enriches these deposits with intact, high-quality crystals that can be economically mined for gem use. The geological formations hosting jargoon-bearing zircon are predominantly in age, reflecting the mineral's stability over billions of years. The oldest dated zircons, found in ancient sedimentary rocks, reach back 4.4 billion years, offering evidence of early crustal development during the eon. While such ancient zircons provide broad context, gem varieties like jargoon more commonly derive from younger metamorphic events, where recrystallization enhances crystal clarity and color suitability.

Major Deposits

Gem-quality jargoon, referring to the colorless to pale yellow varieties of suitable for gem use, is sourced from several prominent primary and secondary deposits worldwide. These locations primarily yield material through in alluvial gravels or eluvial weathering, where durable zircon crystals concentrate due to their resistance to . , formerly Ceylon, stands as a for colorless jargoon, with notable deposits in the Matara (Matura) region producing high-clarity, transparent crystals historically mistaken for diamonds and dubbed "Matura diamonds." These gems are extracted from gem gravels in metamorphic terrains, offering stones prized for their brilliance. In , Cambodia's and Myanmar's Valley serve as key primary deposits for pale yellow jargoon, often recovered from riverine and alluvial placers alongside other gems. Cambodian material frequently exhibits subtle golden hues, while sources provide similar pale varieties with good transparency, contributing significantly to the global supply of heat-treatable . Thailand's Chanthaburi-Trat region also yields pale from alluvial deposits, adding to the regional supply of gem-quality material. Secondary alluvial sources include Australia's Harts Range in the , where placer deposits in heavy mineral sands yield gem-quality jargoon, though much of Australia's output supports industrial applications. In , eluvial and alluvial deposits in states like Plateau and produce placer jargoon ranging from colorless to light yellow, with chemical analyses confirming gem suitability. Tanzania's Mererani Hills provide additional sources of colorless from alluvial mining.

History and Cultural Significance

Historical Use in Jewelry

Jargoon, a light yellow to colorless variety of , has been incorporated into jewelry since ancient times, valued for its brilliance and similarity to more precious gems. Evidence of zircon use in adornments dates back to ancient civilizations, where it served as an imitation for due to its high and dispersion. In 16th-century during the , jargoon gained popularity when cut en , a style that enhanced its soft glow and was frequently mistaken for due to similar golden hues. Jewelers in and favored it for pendants and rosaries, where the rounded cut preserved the stone's natural inclusions while providing a subtle sparkle in candlelit settings. This period marked a shift toward more refined gem cutting techniques, with jargoon appearing in portraits of as earrings and necklaces. The saw a revival of jargoon in Victorian jewelry, with colorless varieties used as a lower-cost alternative to and smoky specimens popular in pieces. Faceted jargoon became a staple in brooches, rings, and other adornments, prized for its diamond-like fire in elaborate settings of and enamel. This period boosted supply from sources like Ceylon (modern ), making the gem affordable for middle-class consumers and leading to its widespread use in sentimental jewelry symbolizing clarity and endurance. Heat treatment methods, developed in the , later enhanced colors for colorless or blue varieties.

Symbolism and Lore

In Hindu tradition, is associated with the planet , believed to promote love, beauty, and prosperity when used in astrological remedies. This connection appears in Vedic texts, where it may be incorporated into amulets for harmonizing energies and fostering well-being. attributes protective and moral-enhancing qualities to jargoon, viewing it as a ward against evil spirits and nightmares while promoting virtue, honor, and wisdom in its wearer. Medieval lapidaries from the 13th century described zircon's ability to induce restful sleep, reflecting its role in amulets to cultivate inner strength. These beliefs positioned the stone as a symbol of moral fortitude and divine favor, often recommended for travelers and the pious. In modern esotericism, jargoon embodies themes of clarity, renewal, and purification, with its colorless variety particularly revered as a of spiritual purity and emotional balance. Practitioners use it to clear mental fog, release stagnant energies, and facilitate personal transformation, often in or energy work to enhance and grounding. This contemporary interpretation builds on its historical virtues, positioning as a tool for self-renewal and aligning one's aura with .

Identification and Treatment

Gemological Testing

Gemologists employ the as a primary tool to authenticate by measuring its (RI), which typically ranges from 1.78 to 1.815 for low (metamict) varieties, confirming its identity among simulants with overlapping properties. High exhibits elevated RI values up to 1.98, while metamict specimens show reduced readings due to , aiding in during grading. For jargoon, gemological testing emphasizes verification of its natural colorless state, distinguishing it from heat-treated or synthetic simulants. Ultraviolet (UV) testing under long-wave and short-wave lamps reveals variable reactions in , often inert or weak yellow to orange, which helps detect metamict states where is typically absent owing to structural degradation. This method supports authentication by highlighting inconsistencies in damaged crystals, as stable zircons may exhibit stronger emissions. Spectroscopy identifies uranium traces characteristic of zircon through distinct absorption bands, including a broad feature around 410 nm in the UV region and sharp lines near 655 nm (notably at 653 nm) in the , verifying natural origin and distinguishing from treated or synthetic alternatives. These uranium-related lines, up to 40 in total, sharpen post-heat treatment but remain diagnostic for the mineral's composition. Microscopic examination at 20x magnification reveals typical inclusions, such as abraded or worn facet edges and cloudy texture in low varieties, which, combined with pronounced doubling from high , differentiate it from simulants like synthetic lacking such features. This inclusion analysis is crucial for grading clarity and authenticity, as growth banding further confirms formation.

Heat Treatment Methods

Heat treatment is the primary enhancement technique applied to , a translucent variety of , to improve its color and clarity by removing undesirable brown tones often present in rough material. The process typically involves heating rough or cut stones at temperatures between 800°C and 1000°C in an oxidizing atmosphere, such as air, for 2 to 4 hours, which recrystallizes the partially metamict structure and yields colorless or pale yellow results. In a , such as one created by powder, the same temperature range can produce hues through the reduction of ions from Tb⁴⁺ to Tb³⁺, although zircon is not considered a natural color and is distinct from the traditional jargoon variety. This treatment alters the gem's internal structure by annealing radiation-induced damage, sharpening absorption spectra and increasing specific gravity from around 4.2–4.4 g/cm³ in metamict forms to 4.6–4.7 g/cm³ in fully crystalline states. The structural changes from also enhance durability, raising the Mohs hardness from 6 in metamict forms to 7.5 in fully crystalline states, making it more suitable for jewelry use. Nearly all colorless and zircons on the market have undergone this treatment, as colorless is rare and rough predominates in deposits. The process is permanent and stable under normal wear, but requires careful control to avoid risks such as internal cracking from or overheating, which can propagate microcracks in stones with inclusions or high uranium content. Ethical standards mandate disclosure of by major gemological laboratories like the (GIA), as the enhancement is undetectable through standard gem testing and can significantly affect value. While the treatment may involve minor chemical shifts in trace elements like and , these are secondary to the primary structural and optical improvements.

Modern Uses

Jewelry Applications

Jargoon, the colorless variety of prized for its diamond-like brilliance, is most effectively cut into brilliant round or oval shapes to maximize its high dispersion and . These faceted cuts enhance the gem's of 1.81–1.99, allowing light to refract into a spectrum of colors similar to . Typical sizes range from 1 to 5 carats, making jargoon suitable for both statement pieces and delicate accents in modern wearable jewelry. For optimal protection and aesthetic appeal, contemporary designers recommend settings for jargoon to shield it from damage, particularly in or white gold, which complements its pale, icy sparkle without overpowering it. These metals provide a cool-toned contrast that emphasizes the stone's clarity, while designs cover the gem's edges to prevent chipping due to its Mohs hardness of 6–7.5. Prong settings, such as four- or six-prong configurations, are an alternative but offer less protection. Jargoon pairs seamlessly with in mixed-gem settings, where smaller accent diamonds enhance its scintillation in cocktail rings, earrings, or necklaces. Zircon is used in engagement rings as an affordable alternative to , providing similar fire at a lower cost. This reflects a broader interest in budget-conscious luxury, with clean-lined solitaire or low-profile halo designs suitable for understated elegance.

Collectibility and Market Value

Jargoon, the colorless variety of , commands market prices that vary significantly based on treatment status and quality. As of 2025, treated colorless jargoon typically averages $50–$300 per carat for eye-clean stones in the 1–5 carat range, making it an accessible alternative to diamond simulants. Untreated colorless jargoon remains rare due to its natural scarcity and susceptibility to cloudiness, often fetching $500 or more per carat for high-quality, transparent specimens from premier sources. Key factors influencing jargoon's value include clarity, origin, and certification. Eye-clean clarity is highly preferred, as inclusions can diminish brilliance and reduce desirability in fine jewelry settings. Stones from are particularly prized for their superior transparency and colorlessness, commanding a premium over those from other localities like or . Certification from reputable labs, such as or AIGS, verifies authenticity and treatment history, significantly boosting market confidence and resale potential. Market trends for jargoon reflect broader shifts in the gem trade, with rising for ethically sourced gems driving among conscious collectors. This emphasis on sustainable practices has elevated the appeal of verified natural and untreated pieces, though —common for enhancing clarity in colorless jargoon—continues to impact value by increasing supply without detectable alteration. Antique jargoon-set jewelry occasionally appears in auctions, appealing to collectors for its historical craftsmanship, though specific sales data underscores the niche rather than widespread high premiums.

References

  1. https://www.gia.edu/doc/spring_1948.pdf
  2. https://www.gia.edu/doc/Spring-1937-Gems-Gemology.pdf
  3. https://www.gia.edu/doc/fall_1943.pdf
  4. https://www.dnr.sc.gov/geology/pdfs/Publications/Bulletins/Bulletin_30.pdf
  5. https://www.journals.uchicago.edu/doi/pdf/10.1086/387370
  6. https://etd.ohiolink.edu/acprod/odb_etd/ws/send_file/send?accession=miami1109871239&disposition=inline
  7. https://periodic.lanl.gov/40.shtml
  8. https://www.gemsociety.org/article/zircon-jewelry-and-gemstone-information/
  9. https://www.gemrockauctions.com/learn/a-z-of-gemstones/zircon-information
  10. https://www.mindat.org/article.php/4833/Zircon+-+The+early+history+and+the+origin+of+the+name
  11. https://www.mindat.org/min-4421.html
  12. https://www.zircon-association.org/assets/files/KnowledgeBank/NRPB_Minerals%20NORM.pdf
  13. https://www.sciencedirect.com/topics/medicine-and-dentistry/zirconium
  14. https://pubs.geoscienceworld.org/msa/ammin/article/55/3-4_Part_1/428/540611/The-distribution-of-uranium-rare-earths-and-color
  15. https://pubs.geoscienceworld.org/canmin/article/54/3/635/521238/Coloration-of-Natural-Zircon
  16. https://www.gemselect.com/gem-info/zircon/zircon-info.php
  17. https://www.gia.edu/zircon
  18. https://www.gemselect.com/gem-info/dispersion-chart.php
  19. https://www.gia.edu/zircon-care-cleaning
  20. https://www.gia.edu/gems-gemology/summer-2015-labnotes-chemical-analysis-zircon
  21. https://www.ga.gov.au/education/minerals-energy/australian-mineral-facts/zircon
  22. https://pmc.ncbi.nlm.nih.gov/articles/PMC6537471/
  23. https://pubs.usgs.gov/fs/2007/3004/pdf/FS07-3004_508.pdf
  24. https://www.nationalgeographic.com/science/article/news-earth-rocks-sediment-first-life-zircon
  25. https://www.gemsociety.org/article/zircon-sources/
  26. https://www.americangemsociety.org/birthstones/december-birthstones/zircon-overview/
  27. https://naturalgemstones.com/education/types-of-gemstones-found-in-nigeria/
  28. https://www.longdom.org/open-access/a-review-of-gemstone-occurrences-provenance-and-origins-in-nigeria-101718.html
  29. https://www.gia.edu/zircon-quality-factor
  30. https://www.gia.edu/zircon-history-lore
  31. https://www.gempundit.com/blog/gemstones-of-vedic-astrology
  32. https://www.americangemsociety.org/zircon-folklore/
  33. https://www.azonomy.com/blogs/blog/zircon-meaning
  34. https://www.beadsofcambay.com/blogs/crystals/zircon-meaning
  35. https://www.gia.edu/doc/zircon-33699.pdf
  36. http://gemologyproject.com/wiki/index.php?title=Zircon
  37. https://www.researchgate.net/publication/290396335_Effect_of_heat_treatment_on_color_of_natural_zircon
  38. https://www.torraca.net/2015/12/18/qa-heating-zircon/
  39. https://pmc.ncbi.nlm.nih.gov/articles/PMC8862150/
  40. https://www.gia.edu/gem-treatment
  41. https://www.gemsociety.org/article/zircon-engagement-ring-guide/
  42. https://www.gemsociety.org/article/protective-gem-settings/
  43. https://awesomegems.com/zircon-priceguide.html
  44. https://www.linkedin.com/pulse/us-zircon-jewelry-market-key-drivers-trends-brandpulse-research-vevke/
  45. https://www.liveauctioneers.com/price-guide/zircon-jewelry/25909/
Add your contribution
Related Hubs
User Avatar
No comments yet.