Hubbry Logo
AntigoriteAntigoriteMain
Open search
Antigorite
Community hub
Antigorite
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Antigorite
Antigorite
Antigorite
View on Wikipedia
from Wikipedia
Antigorite
Antigorite crystals in serpentinite from Poland
General
CategoryPhyllosilicate minerals, kaolinite-serpentine group, serpentine subgroup
Formula(Mg, Fe)3Si2O5OH4
IMA symbolAtg[1]
Strunz classification9.ED.15
Crystal systemMonoclinic
Identification
ColorGreen, yellowish-green, blueish-gray
Crystal habitMassive or platy
Cleavage(001) Perfect
FractureBrittle
Mohs scale hardness3.5–4
LusterVitreous to greasy
StreakGreenish white
Specific gravity2.5–2.6
Optical propertiesBiaxial (−)
Refractive index1.53–1.575
Birefringenceδ = 0.005–0.006

Antigorite is a lamellated, monoclinic mineral in the phyllosilicate serpentine subgroup with the ideal chemical formula of (Mg,Fe2+)3Si2O5(OH)4.[2] It is the high-pressure polymorph of serpentine and is commonly found in metamorphosed serpentinites. Antigorite, and its serpentine polymorphs, play an important role in subduction zone dynamics due to their relative weakness and high weight percent of water (up to 13 weight % H2O).[3][4] It is named after its type locality, the Geisspfad serpentinite, Valle Antigorio in the border region of Italy/Switzerland[5] and is commonly used as a gemstone in jewelry and carvings.

Geologic occurrences

[edit]

Antigorite is found in low-temperature, high-pressure (or high-deformation) environments, including both extensional and compressional tectonic regimes.[6] Serpentines are commonly found in the ultramafic greenschist facies of subduction zones, and are visible on the Earth's surface through secondary exhumation. Serpentinites that contain antigorite are usually highly deformed and show distinct textures, indicative of the dynamic region where they were formed. Antigorite serpentinites commonly have associated minerals of magnetite, chlorite, and carbonates.[7] Olivine under hydrothermal action, low grade metamorphism and weathering will transform into antigorite, which is often associate with talc and carbonate.

Olivine 3Mg2SiO4 + 4H2O + SiO2 → Serpentine 2Mg3Si2O5(OH)4
Serpentine 2Mg3Si2O5(OH)4 + 3CO2 → Talc Mg3Si4O10(OH)2 + Magnesite 3MgCO3 + 3H2O[8]

Physical properties

[edit]

Lamellated antigorite occurs in tough, pleated masses. It is usually dark green in color, but may also be yellowish, gray, brown or black. It has a Mohs scale hardness of 3.5–4 and its lustre is vitreous to greasy.[9] Antigorite has a specific gravity of 2.5–2.6. The monoclinic crystals show micaceous cleavage, a distinguished property of phyllosilicates, and fuse with difficulty.[10] Serpentinite rocks that consist of mostly antigorite are commonly mylonites. The antigorite grains that make up these rocks are very fine (on the order of 1 to 10 microns) and are fibrous, which defines a texture in the rock caused by lattice preferred orientation.[11]

Gemstone properties

[edit]
Polished antigorite

Antigorite is used as gemstones or for carvings when it appears pure and translucent, although many crystals have black specks of magnetite suspended within. The gem types of antigorite are Bowenite and Williamsite. Bowenite, known for George T. Bowen from Rhode Island (the variety's type locality), who first analyzed the mineral, is translucent and light to dark green, often mottled with cloudy white patches and darker veining. It is the serpentine most frequently encountered in carving and jewelry, and is the state mineral of Rhode Island, United States. A bowenite cabochon featured as part of the "Our Mineral Heritage Brooch", was presented to U.S. First Lady Mrs. Lady Bird Johnson in 1967. Williamsite is very translucent and has a medium to deep apple-green color. Somewhat resembling jade, Williamsite is often cut into cabochons and beads.

Crystal structure

[edit]
Simplified crystal structure of antigorite looking down the b axis. Blue triangles indicate SiO4 tetrahedra, green layers indicate Mg octahedra. Red line indicates polarity reversal. In this case, m = 17.[12]

The magnesian serpentines (antigorite, lizardite, chrysotile) are trioctahedral hydrous phyllosilicates. Their structure is based on 1:1 octahedral-tetrahedral layer structures. Antigorite is monoclinic in the space group Pm.[13] Although the magnesian serpentines have similar compositions, they have significantly different crystallographic structures, which are dependent on how the SiO4 tetrahedra sheets fit in with the octahedral sheets.[14] Antigorite's basic composition has a smaller ratio of octahedral to tetrahedral cations (relative to lizardite and chrysotile),[15] allowing the structure to compensate for the misfit of sheets through periodic flipping of the curved tetrahedra layers, and subsequently their polarity.[16] Polysomes of antigorite are defined by the number of individual tetrahedra (denoted as the value m) which span a wavelength of the direction of curvature.[17] The sheets of tetrahedra allow the platy, fibrous crystals to separate parallel to the 001 (basal) plane, giving antigorite its perfect cleavage.

See also

[edit]

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Antigorite

View on Grokipedia
from Grokipedia
Antigorite is a magnesium-rich phyllosilicate mineral belonging to the serpentine group, characterized by the ideal (Mg,Fe²⁺)₃Si₂O₅(OH)₄ and serving as one of its three principal polymorphs alongside and . It typically forms as fine-grained, platy, bladed, or fibrous aggregates in metamorphic rocks, exhibiting a vitreous to resinous luster, green to blue-green coloration, and a Mohs hardness of 2.5 to 4. As a high-temperature variety of , antigorite develops primarily above 250°C in - to granulite-facies , often replacing ultramafic rocks such as or forming in bodies within complexes and regional metamorphic terrains. It is commonly associated with minerals like , , , and other serpentine polymorphs, and its presence indicates hydration and of mantle-derived rocks under moderate pressures. Named in 1840 by Mathias Eduard Schweizer after its type locality in the Val Antigorio, , , antigorite was first described from exposures along the Geisspfad in the Switzerland-Italy border region. Structurally, antigorite features a with a unique modular polysomatic arrangement of 1:1 layers, leading to variable parameters and occasional fibrous varieties that can resemble and pose similar health risks if inhaled. Its include biaxial negative with refractive indices around 1.558–1.574 and a specific of 2.5–2.6, making it identifiable in thin sections as pale green with perfect basal cleavage. While not a major , antigorite is occasionally used in lapidary arts, such as for "Andes jade," due to its attractive green hues and workability, and it plays a key role in geological studies of zones and mantle processes.

Overview

Definition and Classification

Antigorite is a lamellated, fibrous variety of , characterized by its layered structure and belonging to the phyllosilicate class. Its ideal is (Mg,Fe²⁺)₃Si₂O₅(OH)₄, reflecting a hydrous magnesium-iron composition typical of the serpentine group. This forms through metamorphic processes and is distinguished by its ability to develop in higher-temperature environments compared to other serpentines. In mineral classification, antigorite is placed within the kaolinite-serpentine group of phyllos, specifically as a 1:1 layered where tetrahedral and octahedral sheets alternate. It exhibits a , with a modulated structure featuring periodic reversals in the tetrahedral sheets along the direction. This classification underscores its role as a trioctahedral , with magnesium predominantly occupying octahedral sites, though iron substitutions are common. Antigorite differs from other serpentine polymorphs such as , which displays a fibrous, asbestos-like due to its cylindrical rolled layers, and , which forms platy or fine-grained masses with ideal planar topology. In contrast, antigorite typically occurs in massive, pleated, or bladed , often as scales or plates, resulting from its unique wavy, modulated layering. As a primary metamorphic , it is a key constituent of rocks, formed during the hydration and alteration of ultramafic protoliths under to facies conditions.

Etymology and Discovery

Antigorite was named in 1840 by the Swiss mineralogist Mathias Eduard Schweizer after its type locality in the Valle Antigorio (also known as Val Antigorio), near in the region of , close to the Swiss border. The type material originates from the Geisspfad serpentinite in this area, where specimens were collected and analyzed, establishing antigorite as a distinct member of the serpentine group. This naming reflects the 19th-century practice of honoring geographic origins for new mineral identifications, with the type specimen preserved at the Eidgenössische Technische Hochschule in , . The broader term "serpentine" for the mineral group predates antigorite's specific recognition, deriving from the Latin word serpens, meaning "snake," in reference to the minerals' often mottled, snake-like green appearance and texture. Coined in 1564 by the German scholar in his seminal work , the name encapsulated the visual resemblance of these hydrous magnesium silicates to serpentine patterns. Early descriptions lumped various serpentine varieties together under this general designation, reflecting limited analytical tools available before the widespread adoption of chemical assays and in the 1800s. Antigorite's identification emerged amid 19th-century advancements in petrology, a period marked by increasing scrutiny of metamorphic rocks and their constituent minerals. As geologists like Schweizer employed emerging techniques such as wet chemistry and early optical microscopy, distinctions began to appear between serpentine polymorphs, moving beyond the monolithic "serpentine" category toward precise classifications based on composition and formation conditions. This era's focus on ultramafic and metamorphic assemblages in Alpine regions, including the Italian-Swiss border, facilitated antigorite's formal delineation as a high-temperature variant stable above approximately 250°C. By the late 1800s, works like Edward Salisbury Dana's System of Mineralogy (1892) documented antigorite alongside other serpentines, solidifying its place in mineralogical nomenclature.

Chemical Composition and Properties

Chemical Formula and Variations

Antigorite has the ideal end-member chemical formula \ceMg3Si2O5(OH)4\ce{Mg3Si2O5(OH)4}, representing a magnesium-rich phyllosilicate in the serpentine group. This composition corresponds to a theoretical weight percentage of approximately 43.4% SiO₂, 43.6% MgO, and 13.0% H₂O. A common substitution involves divalent iron replacing magnesium in the octahedral sites, yielding the general formula \ce(Mg,Fe2+)3Si2O5(OH)4\ce{(Mg,Fe^{2+})3Si2O5(OH)4}. This iron incorporation typically results in FeO contents ranging from 2.5 to 6.5 wt%, with a mean around 4.5 wt%, corresponding to a Mg:Fe ratio of approximately 9:1 in natural samples. Minor substitutions further diversify the composition, including aluminum substituting for silicon in tetrahedral sites via Tschermak's exchange (Al³⁺ for Si⁴⁺ coupled with Al³⁺ for Mg²⁺), which can reach up to 4-5 wt% Al₂O₃. Additionally, iron (as Fe²⁺ or Fe³⁺) or can occupy octahedral sites, with nickel more prevalent in ultramafic-derived varieties. These substitutions maintain charge balance while influencing the mineral's stability under varying pressure-temperature conditions. The reflects antigorite's layered , featuring alternating 1:1 tetrahedral-octahedral sheets with brucite-like octahedral layers, incorporating about 13 wt% hydroxyl groups essential for its hydration. Compositional variations in natural antigorite are determined through techniques such as electron microprobe analysis for major and minor elements, and spectroscopy for bulk chemistry, allowing precise quantification of substitutions in individual crystals or aggregates.

Physical and Optical Properties

Antigorite exhibits a Mohs hardness of 2.5 to 4, making it relatively soft compared to many silicates, which facilitates its identification through scratch tests. Its specific gravity ranges from 2.5 to 2.6, reflecting its lightweight composition dominated by magnesium and silicon. The mineral typically displays a dark green color, though variations to yellow, gray, brown, or black occur due to impurities such as iron or manganese. It produces a white to greenish-white streak, aiding in distinguishing it from darker minerals with similar appearances. The luster of antigorite is vitreous to resinous, contributing to its somewhat glassy or waxy sheen in hand samples. It features perfect cleavage along the {001} plane, resulting in thin, platy fragments, while its is uneven to splintery. In terms of , antigorite commonly forms fibrous or massive aggregates, often appearing as tough, pleated or corrugated masses that enhance its durability in metamorphic rocks. Optically, antigorite is biaxial negative, with refractive indices of nα = 1.558–1.567, nβ = 1.565, and nγ = 1.562–1.574, which produce low values around 0.005–0.006. It shows weak , typically from colorless or pale green to yellowish-green in iron-bearing varieties, observable under . Diagnostic tests for antigorite include its fibrous or massive in pleated masses and its solubility in (HCl), which differentiates it from —a similar sheet that remains insoluble in dilute acids. This reaction, often requiring hot concentrated HCl for complete dissolution, confirms antigorite's presence in mineral separations.

Crystal Structure

Structural Features

Antigorite is a layered characterized by a 1:1 ratio of tetrahedral SiO₄ sheets and octahedral MgO₆ sheets, with hydroxyl (OH) groups incorporated into the structure, resulting in a monoclinic . The tetrahedral sheet consists of corner-sharing silica tetrahedra forming a pseudo-hexagonal network, while the octahedral sheet comprises edge-sharing magnesium octahedra, creating a continuous brucite-like layer. These sheets alternate to form the fundamental layer unit, where the apical oxygens of the tetrahedra bond to the octahedra, and the basal oxygens of the tetrahedra remain exposed on one side of the layer. A distinctive feature of antigorite's structure is the corrugation or of the layers along the direction, which arises from a dimensional misfit between the larger octahedral sheet and the smaller tetrahedral sheet. This misfit, approximately 10-15% in lateral dimensions, is accommodated by periodic shifts and inversions in the orientation of the tetrahedra, leading to a modulated, undulating configuration rather than the flat layers seen in related minerals like . The average bond lengths reflect this arrangement, with Si-O distances in the tetrahedra approximately 1.62 and Mg-O distances in the octahedra ranging from 2.07 to 2.12 , contributing to the overall stability of the wavy framework. Interlayer bonding in antigorite occurs primarily through weak van der Waals forces between the basal oxygens of adjacent tetrahedral sheets, supplemented by bonding involving the OH groups, which allows for the mineral's flexibility and cleavage. Polytypism in antigorite arises from variations in the periodicity of tetrahedral inversions, forming supersuctures with large unit cells, such as a-parameter lengths ranging from 33 to 62 depending on the specific modulation period. These structural variations enable antigorite to adapt to compositional differences while maintaining the core layered architecture.

Polysome Types

Antigorite exhibits polysomatism, where its structure consists of modular repeat units along the a-axis, characterized by the parameter m, which denotes the number of inverted tetrahedra per in the modulated tetrahedral sheet to accommodate the mismatch with the octahedral sheet. Common m-values range from 13 to 24, with variations arising from the insertion of inverted tetrahedra that adjust the layer periodicity. The most frequent polysome is m=17, which dominates natural occurrences and features a unit cell parameter a ≈ 43.5 Å, reflecting its characteristic wavelength of 17 tetrahedra. Other common types include m=15 and m=21, while m=24 is rarer and typically observed in specific low-temperature settings. These variants maintain the overall 1:1 phyllosilicate layering but differ in modulation amplitude and symmetry, with odd m-values like 17 yielding primitive lattices and even values like 16 or 24 producing centered ones. Identification of polysome types relies on techniques that reveal the structural periodicity, such as selected-area (SAED) patterns, which display reflections corresponding to the a-axis repeat, and (HRTEM), which visualizes the wavy tetrahedral chains and inverted tetrahedra directly. These methods confirm the m-value by measuring inter-row spacings or spacings along . Polysome stability varies with environmental conditions, where higher m-values (e.g., m=21–24) are favored at lower temperatures and ambient pressures due to their ability to minimize strain in the curved layers, while lower m-values (e.g., m=13–15) stabilize at elevated temperatures or pressures, facilitating pathways. This distribution influences deformation textures in serpentinites, as higher-m polysomes promote finer-grained, more ductile fabrics in low-temperature shear zones, whereas lower-m variants align with coarser, brittle textures in higher-grade .

Formation and Geological Occurrences

Formation Processes

Antigorite primarily forms through the hydration of ultramafic rocks, such as , during greenschist-facies under conditions of approximately 250–500°C and 0.5–2 kbar pressure. This process, known as serpentinization, involves the reaction of anhydrous silicate minerals like and with water-rich fluids, typically derived from or metamorphic devolatilization in settings. In ophiolites and subduction zones, these conditions facilitate the transformation of mantle peridotites into serpentinites dominated by antigorite, which is the stable serpentine polymorph at higher temperatures within this range. The key reaction for antigorite formation from () is: 2Mg2SiO4+3H2O→Mg3Si2O5(OH)4+Mg(OH)22 \text{Mg}_2\text{SiO}_4 + 3 \text{H}_2\text{O} \rightarrow \text{Mg}_3\text{Si}_2\text{O}_5(\text{OH})_4 + \text{Mg}(\text{OH})_2 This exothermic reaction produces antigorite and , often accompanied by as an accessory phase due to oxidation during fluid-rock interaction. Similar hydration occurs with orthopyroxene, contributing to the overall serpentinization. processes may also play a role in metasomatic environments, where CO₂-bearing fluids interact with ultramafic protoliths, but hydration remains the dominant mechanism for antigorite . Texturally, antigorite develops through pseudomorphic replacement of primary minerals, preserving hourglass or mesh structures after and bastite textures after , or as infillings in veins where fluids infiltrate fractures. These features indicate progressive fluid-mediated alteration, with antigorite often intergrown with associated minerals such as , , and , which form stable assemblages under subcritical conditions. In zones, antigorite's stability enables deep transport of water, influencing fluid release and arc upon dehydration at higher depths. Ophiolites preserve these formation processes as remnants of oceanic altered at mid-ocean ridges or convergent margins.

Principal Localities

Antigorite's type locality is the Geisspfad serpentinite in Valle Antigorio, along the Italy-Switzerland border, where it was first described in 1840 by Swiss chemist Mathias Eduard Schweizer from specimens collected in this Alpine region. This site features antigorite formed through the serpentinization of ultramafic rocks in a metamorphic environment, marking the mineral's initial recognition as a distinct serpentine polymorph. Major global occurrences of antigorite are associated with complexes and serpentinized ultramafics. In the , the Peninsula in hosts massive bodies containing antigorite, often alongside , within the Lizard complex. New Caledonia's ultramafic massifs, such as Koniambo, yield fibrous antigorite varieties linked to laterites, exhibiting asbestos-like morphologies. In the United States, Appalachian , including sites in like Belvidere Mountain and North Carolina's deposits, contain antigorite as a primary serpentinization product in ultramafic rocks. The in feature significant antigorite in deposits like Bazhenovskoye and the Kagan massif, where it forms in gold-bearing serpentinites and asbestos parageneses with . The Semail in also preserves antigorite in deformed zones, reflecting subduction-related processes. Notable deposits include Val Malenco in , particularly at Pizzo Tremogge, which produces gem-quality antigorite-rich known as "noble ," composed of alternating antigorite, , and phases suitable for ornamental carving. The Lizard area provides massive blocks with antigorite for local extraction. Antigorite frequently associates with minerals in chrysotile-antigorite parageneses, as seen in Ural and New Caledonian sites, contributing to mixed assemblages. Economically, antigorite serves as a source for ornamental stone, such as verde-antique from serpentinized deposits, valued for decorative applications despite challenges in processing. Pure, well-formed crystals remain rare, with most occurrences yielding massive or fibrous aggregates rather than euhedral specimens.

Uses and Applications

Gemological and Decorative Uses

Antigorite, a variety of the group, serves as a and ornamental material due to its attractive green hues and translucency in select specimens. High-quality masses are prized for their gemmy appearance, often cut into cabochons, beads, and carvings that highlight the stone's waxy luster. Polishing treatments significantly enhance antigorite's aesthetic appeal, particularly in fibrous forms that exhibit , producing a cat's-eye effect when cut as cabochons aligned parallel to the fiber direction. This arises from reflection off aligned inclusions, making treated pieces more desirable for jewelry. Antigorite is also frequently marketed as "serpentine " due to its similarity in color and texture to , serving as an affordable imitation in carvings and pendants. Historically, antigorite and related serpentines have been utilized in ancient Asian civilizations, including , where they were carved into jewelry and ceremonial objects under the broad term "yu" for jade-like stones, dating back to and periods. In , during the , Italian artisans employed serpentine varieties like antigorite for architectural decorations, vases, and ornamental sculptures, leveraging the stone's workability for detailed craftsmanship. The value of antigorite gemstones is influenced by the rarity of high-quality, translucent masses, with its Mohs hardness of 2.5 to 4 limiting durability for everyday wear and restricting use to protected settings. Faceted pieces typically range from $1 to $10 per carat, depending on color intensity and clarity, while carved ornaments command higher prices based on size and intricacy. Due to its occasional fibrous habit, handling antigorite for cutting or polishing requires precautions against dust inhalation to minimize respiratory health risks, similar to other minerals.

Industrial Applications

Antigorite, a layered , is utilized as an additive in lubricants due to its and low , which enable effective reduction in high-temperature environments. When incorporated into base oils or greases at concentrations of 0.5–2.0 wt%, antigorite and related nanoparticles (typically <2 μm) can significantly decrease friction and wear under boundary lubrication conditions, forming protective tribofilms through ion exchange and surface polishing mechanisms. This makes it suitable for applications in automotive engines, industrial gears, and air compressors. Surface modification with agents like oleic acid enhances its dispersibility in non-polar media, optimizing performance in serpentine-based oils for high-temperature bearings. In construction, milled antigorite from mining tailings serves as a precursor for alkali-activated binders, offering an eco-friendly alternative to by leveraging its reactivity after mechanical activation. Dry milling for 4–10 minutes induces amorphization (up to 85%) and partial dehydroxylation (up to 24%), enabling the formation of compressive strengths of 49 MPa after 28 days under dry curing conditions (65% RH), comparable to traditional binders. These binders, mixed with activators, exhibit enhanced durability and potential for CO2 capture during processing in carbonated atmospheres, supporting sustainable production of asbestos-free serpentinite for roofing and flooring applications. Antigorite also functions as a filler in plastics and rubber composites, imparting heat resistance and mechanical reinforcement; for instance, dual-phase antigorite-wollastonite additions to polytetrafluoroethylene reduce wear by 30–50% while maintaining low friction in sliding bearings. In ceramics, calcined antigorite-rich serpentine wastes (with ~48% MgO) are employed as raw materials for high-temperature refractories, achieving refractoriness >1730°C and forming phases suitable for industry linings or bodies. Emerging applications explore antigorite-derived layered double oxides in silica composites for with improved and structural integrity. Environmentally, antigorite plays a role in mine remediation through thermal activation for CO2 mineralization, where heating to 600–800°C dehydroxylates the , facilitating reactions that sequester CO2 and stabilize asbestos-like fibers, reducing health risks in serpentinized waste sites. Its abundance in ultramafic-derived formations further positions antigorite as an indicator in geotechnical evaluations of serpentinized zones for assessing and excavation risks in operations.

References

  1. https://www.mindat.org/min-260.html
  2. https://www.handbookofmineralogy.org/pdfs/antigorite.pdf
  3. https://pubmed.ncbi.nlm.nih.gov/29733442/
  4. https://rockidentifier.com/wiki/Antigorite.html
  5. https://pubs.usgs.gov/pp/0384a/report.pdf
  6. https://www.sciencedirect.com/topics/earth-and-planetary-sciences/antigorite
  7. https://www.etymonline.com/word/serpentine
  8. https://classicgems.net/gem_serpentine.htm
  9. https://www.mdpi.com/2075-4442/8/10/93
  10. https://webmineral.com/data/Antigorite.shtml
  11. https://pmc.ncbi.nlm.nih.gov/articles/PMC7015306/
  12. https://www.perplex.ethz.ch/papers/padron-navarta_lithos_2013.pdf
  13. https://rruff.geo.arizona.edu/doclib/cm/vol17/CM17_771.pdf
  14. https://rruff.geo.arizona.edu/doclib/hom/antigorite.pdf
  15. https://www.alexstrekeisen.it/english/meta/antigorite.php
  16. http://mingen.hk/antigorite.html
  17. https://pubs.usgs.gov/pp/0384b/report.pdf
  18. https://rruff.geo.arizona.edu/doclib/am/vol89/AM89_147.pdf
  19. https://pubs.geoscienceworld.org/msa/ammin/article/94/8-9/1271/45005/First-principles-energetics-and-structural
  20. https://ejm.copernicus.org/articles/33/389/2021/
  21. https://rruff.geo.[arizona](/page/Arizona).edu/doclib/am/vol91/AM91_394.pdf
  22. https://pubs.geoscienceworld.org/msa/ammin/article-abstract/89/1/147/44068/The-modulated-crystal-structure-of-antigorite-The
  23. https://d197for5662m48.cloudfront.net/documents/publicationstatus/157133/preprint_pdf/b3cff89b146fd95b4795b17b1ec05ec4.pdf
  24. https://rruff.geo.arizona.edu/doclib/am/vol91/AM91_394.pdf
  25. https://pubs.geoscienceworld.org/msa/ammin/article-abstract/92/1/64/134303/High-resolution-transmission-electron-microscopy
  26. https://www.sciencedirect.com/science/article/abs/pii/S0024493712004781
  27. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2005GL024728
  28. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020JB020619
  29. https://escholarship.org/content/qt7xj422dq/qt7xj422dq_noSplash_32324c27d148b3a898eb7e192dd243f8.pdf
  30. https://pubs.usgs.gov/of/2006/1229/of2006-1229.pdf
  31. https://pubs.geoscienceworld.org/ejm/eurjmin/article/16/4/585/62166/A-microstructural-study-of-a-crack-seal-type
  32. https://www.sciencedirect.com/science/article/pii/002449377690030X
  33. https://www.nature.com/articles/s41598-017-16883-4
  34. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2024GC011918
  35. https://classicgems.net/gem_antigorite.htm
  36. http://ussher.org.uk/wp-content/uploads/journal/1997/09-Power_et_al_1997.pdf
  37. https://www.mindat.org/locentries.php?p=2435&m=260
  38. https://dec.vermont.gov/act250/geological-survey/vermont-geology/Belvidere
  39. https://www.mindat.org/locentries.php?p=2714&m=260
  40. https://www.sciencedirect.com/science/article/abs/pii/S0012821X14007535
  41. https://www.gia.edu/gems-gemology/spring-2016-gem-quality-serpentine-val-malenco-central-alps-italy
  42. https://www.mdpi.com/2075-163X/9/12/758
  43. https://pubs.usgs.gov/bul/1082k/report.pdf
  44. https://www.[mindat.org](/page/Mindat.org)/min-260.html
  45. https://www.gia.edu/doc/GG-SP16-Adamo.pdf
  46. https://www.gemrockauctions.com/learn/a-z-of-gemstones/serpentine-mineral
  47. https://www.britannica.com/art/Chinese-jade
  48. https://www.vandjcrystal.com/blogs/crystal-properties-birthstones-zodiac-chakras/serpentine-meaning-properties-value-rarity
  49. https://www.cdc.gov/niosh/topics/asbestos/default.html
  50. https://doi.org/10.3390/lubricants8100093
  51. https://doi.org/10.1016/j.ceramint.2016.08.184
Add your contribution
Related Hubs
User Avatar
No comments yet.