Demantoid

demantoid

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Demantoid

Demantoid yog cov xim ntsuab ntau hom ntawm cov ntxhuav thiab ntxhov siab, ib tug tswv cuab ntawm pawg pab pawg ntawm cov zaub mov. Andradite yog calcium- thiab hlau nplua nuj garnet. Cov tshuaj formula yog Ca3Fe2 (SiO4) 3 nrog chromium hloov raws li qhov ua rau ntawm cov xim ntsuab (demantoid). Ferric Iron yog qhov ua rau ntawm daj hauv lub pob zeb.

Nws muaj cov misnomers olivine, thiab Uralian emerald.

Nyob rau thaj tsam 2003, cov ntawv tshaj tawm tau pib khiav tawm hauv cov lag luam tias qee cov Lavxias teb sab demantoid garnets tau niaj hnub ua rau kev kho cua sov kom rov zoo siab rau lawv cov xim. Xws li kev kho mob ntseeg tau tias yuav tsum tau ua nyob rau hauv tsawg dua kub thiab yog xav tias yuav tsum tsis paub los ntawm kev kuaj cov kev kuaj xeeb.

Qhov ntsuab ntau yam ntawm andradite garnet

Demantoid yog ntsuab ntau hom txiv hmab txiv ntoo andradite, yog li feem ntau qhov ntsuab (txhais tau tias), tiam sis lub ntxoov ntxoo ntau npaum li cas los ntawm ib lub paj daj ntsuab ntsuab kom ze rau xim zoo nkauj zoo nkauj. Qee lub pob zeb muaj cov xim pob kws brownish, uas yog vim hlau. Nws cov dispersion (0.057) zoo siab heev, thiab qhov no feem ntau pom tau tias yog "hluav taws" (cov duab tshav xoob xim ntawm lub teeb), tab sis qee lub sij hawm lub pob zeb lub cev ntsuab xim tuaj yeem ua qhov kev tshwm sim tsawg dua. Lawv cov luster yog neeg ntxias. Demantoid kuj muaj lub siab ua haujlwm siab ntawm Performance index ntawm 1.80 rau 1.89.

Demantoids feem ntau me me, nrog cov pob zeb tiav tas li hauv 1 carat (200 mg) thiab pob zeb dhau 2 carats (400 mg) yog tsawg. Pob zeb dhau 3 carats (600 mg) yog qhov tsawg kawg.

Lub pob zeb nrog ntau khaus ntawm xim ntsuab feem ntau yeej muaj nuj nqis, tab sis cov pob zeb ntawm cov xim daj daj daj tuaj tau ntau dua hluav taws. Kev xaiv ntawm pob zeb xim lossis hluav taws tuaj yeem yog qhov teeb meem ntawm tus kheej nyiam, nrog qee qhov preferring ntau yellowish-ntsuab pob zeb rau lub pob zeb ntsuab.

Khuv xim koj

Lavxias sab ntsuj plig feem ntau muaj inclusions ntawm chrysotile, uas yog hom asbestos. Cov fibers radiate tawm los ntawm ib tug me me siv lead ua ntawm chromite. Cov inclusions yog feathery golden threads uas yuav curve thiab zoo li tus Tsov tus tw ntawm ib tug nees, thiab yog vim li ntawd raug xa mus rau raws li horsetail inclusions. Hauv kev tshawb nrhiav pov thawj, qhov kev kuaj pom muaj xws li 'diagnostic' rau natural demantoid (ie cov inclusions tsis pom muaj lwm yam ntsuab gemstone). Ib co gemstones muaj nqis rau lawv cov inclusions, thiab 'horsetails' yuav ntshai li desirable nta nyob rau hauv demantoid, raws li lawv tau noj raws li ib qho ntawm cov neeg paub teb chaws As Mes Lis Kas keeb kwm, txawm tias ib co demantoids los ntawm lwm qhov chaw (xws li Ltalis thiab Iran) muaj 'horsetails', uas suav tias yog cov xeeb ceem ntawm ib thaj chaw nyob hauv lub ntiaj teb, thiab, ntawm qhov tod tes, tsis yog txhua tus Lavxias teb sab demantoids yeej muaj 'horsetails'. Lub microstructure ntawm qee cov neeg ua kom ntseeg tau hais tias muaj kev cuam tshuam los ntawm cov tsiaj 'horsetail' (lub 'horsetail' feem ntau yog los ntawm qhov chaw nruab nrab ntawm lub nodule, nrog lub fibers branching thiab radiating ntawm qhov chaw), whereas horsetail-free demantoids los ntawm lwm yam cov ntaub ntawv nquag saib cov khoom siv pav ca.

Demantoid los ntawm Namibia

yuav natural gemstones hauv peb lub khw

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kev ua yuam kev: Cov ntsiab lus yog kev tiv thaiv !!