Tridymite thiab cristobalite yog qhov kub thiab txias, tsis tshua muaj siab polymorphs ntawm silica, tsim stably saum 870 °C (tridymite) thiab 1470 ° C (cristobalite). Tsis tas li ntawd, lawv tuaj yeem tsim metastably hauv qee qhov chaw qis qis (piv txwv li, lawv feem ntau tsim thaum lub sij hawm devitrification ntawm siliceous volcanic lossis hluavtaws iav).
Tridymite tsim nyob qhov twg?
Tridymite cov ntaub ntawv nyias hexagonal daim hlau uas feem ntau twinned, feem ntau nyob rau hauv pab pawg ntawm peb; nws lub npe alludes rau tus cwj pwm no. Nws feem ntau tshwm sim hauv cov pob zeb uas tsis muaj zog, ntau dua li cristobalite, xws li hauv trachytes ntawm Rhineland-Palatinate, lub teb chaws Yelemees; sab qaum teb Ltalis; thiab hauv Massif Central, Fabkis
YPuas Tridymite yog quartz?
Tridymite yog ib qho tsis tshua muaj polymorph ntawm cov ntxhia Quartz. Txawm li cas los xij, nws cov crystals yog qhov txawv heev thiab tsim cov cwj pwm txawv ntawm Quartz.
Dab tsi yog qhov txawv ntawm quartz thiab tridymite?
Tridymite yog tshuaj zoo ib yam rau quartz, tab sis muaj cov qauv siv lead ua sib txawv. Qee lub sij hawm muaj sodium aluminium silicate, uas zoo li raug tshem tawm thaum quartz solidifies ntawm qis kub.
Puas yog quartz muaj ntxaib?
Nws feem ntau lees paub tias untwinned quartz yog qhov tsis tshua muaj thiab feem ntau cov muaju yog ntxaib raws li txoj cai Dauphinéthiab txoj cai Brazil (Booth thiab Sayers, 1939; Gordon, 1945 thiab lwm yam); Booth thiab Sayers kuj qhia tias Dauphiné-Brazil ("ua ke") twinning yog heev.
