Tsis yog txhua txhua hom ntawm quartz yog ib txwm muaj tshwm sim. Vim tias cov kua siv lead ua feem ntau ntxaib, hluavtaws quartz yog tsim rau siv hauv kev lag luam. Loj, flawless, tib cov muaju yog synthesized nyob rau hauv autoclave ntawm cov txheej txheem hydrothermal.
Synthetic quartz suav nrog ntau hom kev kawm ntawm crystallizing tshuaj los ntawm kev kub siab aqueous kev daws teeb meem ntawm siab vapor pressures, tseem hu ua hom kev hydrothermal, hydrothermal yog ntawm keeb kwm geologic. Geochemists thiab mineralogists tau kawm hydrothermal quartz equilibria txij thaum pib ntawm lub xyoo pua nees nkaum.
Kev ntsuas hluav taws xob
Hydrothermal synthesis can be defined as a method of synthesis of single crystals that depends on the solubility of minerals in hot water under high pressure. The quartz crystal growth is performed in an apparatus consisting of a steel pressure vessel called an autoclave, in which a nutrient is supplied along with water.
A temperature gradient is maintained between the opposite ends of the growth chamber. At the hotter end the nutrient solute dissolves, while at the cooler end it is deposited on a seed crystal, growing the desired crystal.
Qhov zoo ntawm cov khoom cua hydrothermal quartz txoj kev
Advantages of the hydrothermal method over other types of crystal growth include the ability to create crystalline phases which are not stable at the melting point. Also, materials which have a high vapor pressure near their melting points can be grown by the hydrothermal method.
The method is also particularly suitable for the growth of large good-quality crystals quartz while maintaining control over their composition. Disadvantages of the method include the need of expensive autoclaves, and the impossibility of observing the crystal as it grows if a steel tube is used. There are autoclaves made out of thick-walled glass, which can be used up to 300°C and 10 bars.
- MINERAL: Oxide ntxhia
- CHEMISTRY: SiO2
- XIM: Tsis muaj xim los ntawm ntau yam xim rau xim dub
- REFRACTIVE INDEX: 1.54 rau 1.55
- KEV LOM ZEM: + 0.009
- SPECIFIC GRAVITY: 2.59 – 2.65
- MOHS HARDNESS: 7
Khoom cua quartz keeb kwm
Thawj qhov kev tshaj tawm ntawm hydrothermal kev loj hlob ntawm cov muaju yog los ntawm German geologist Karl Emil von Schafhäutl (1803 – 1890) hauv 1845 nws loj hlob microscopic muaju hauv lub qhov cub txias.
Khoom cua quartz