0 a mineral that exists in various forms, including sand, quartz, and flint, used to make glass and cement -- 矽石，二氧化矽
Conodonts and brachiopods are usually preserved as moulds or replaced by silica.
The silica 'fusion crust' from the associated sample holder exhibited a significant degree of isotopic exchange with atmospheric oxygen during re-entry1.
The air was dried to zero relative humidity by passing it through two columns of silica gel.
The results are shown in table 1 together with some physical properties of the silica dusts.
The ostracod valves recovered have been replaced by finely to coarsely crystalline silica, which has preserved the original morphology and in some cases the ornament.
The two planes intersect along cd which is the locus of liquids in equilibrium with a silica polymorph + two feldspars + aqueous fluid.
Small amounts of calcite and dolomite can appear sporadically in silica xenoliths, but are more common in calc-silicate xenoliths.
Seeds were dried for 2 weeks over silica gel before sugar extraction.
