@article{fdi:010077789,
  title = {{T}he texture and chemical composition of trapiche ruby from {K}hoan {T}hong, {L}uc {Y}en {M}ining {D}istrict, {N}orthern {V}ietnam},
  author = {{P}ignatelli, {I}. and {G}iuliani, {G}aston and {M}orlot, {C}. and {L}ong, {P}. {V}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he trapiche texture and chemical composition of two rubies from the {K}hoan {T}hong placer in northern {V}ietnam were examined by {X}-ray computed tomography, scanning electron microscopy and electron microprobe analysis. {T}heir texture is similar to that of some {B}urmese trapiche rubies, with inclusion-rich sector boundaries intersecting at a small central point and a significant concentration of elongated tube-like voids in growth sectors. {T}he most common inclusions are anorthite and margarite; the latter formed by destabilisation of both ruby and anorthite during retrograde metamorphism. {T}he chemical composition of the samples plots in the field of {V}ietnamese alluvial and primary marble-hosted deposits, although differences in {F}e2{O}3, {T}i{O}2 and {C}r2{O}3 contents may distinguish trapiche rubies from various mining areas in {V}ietnam. {T}heir composition differs from that of {B}urmese trapiche rubies by a higher {F}e2{O}3/{T}i{O}2 ratio and a lower {C}r2{O}3 content. {V}ietnamese trapiche rubies formed in the same geological environment as non-trapiche ones, under metamorphic conditions prevailing for the {H}imalayan orogenesis. {I}n this geological context, localised fluid pressure variations and hydraulic fracturing caused changes in the driving force of crystallisation, favouring the development of the trapiche texture.},
  keywords = {{VIET} {NAM}},
  booktitle = {},
  journal = {{J}ournal of {G}emmology},
  volume = {36},
  numero = {8},
  pages = {726--746},
  ISSN = {1355-4565},
  year = {2019},
  DOI = {10.15506/{J}o{G}.2019.36.8.726},
  URL = {https://www.documentation.ird.fr/hor/fdi:010077789},
}