tridymite


Also found in: Dictionary, Medical, Encyclopedia, Wikipedia.
Related to tridymite: cristobalite
Graphic Thesaurus  🔍
Display ON
Animation ON
Legend
Synonym
Antonym
Related
  • noun

Words related to tridymite

a mineral form of silica

References in periodicals archive ?
The fibrogenic potential of silica depends on its modification, e.g., tridymite is more fibrogenic than cristobalite, which is more fibrogenic than quartz [1].
The first is water elimination retained between blades of ore, and the second is determined by reorganization of other present minerals and silica polymorphs, such as low and high quartz and tridymite.
Adding to the puzzle, some of the silica found at one rock Curiosity drilled, called "Buckskin," is in a mineral named tridymite, which is found in Bandelier tuff, common in New Mexico but rare elsewhere, and never before seen on Mars.
That lower level would also apply to two other forms of crystalline silica: cristobalite and tridymite. OSHA also proposed other ancillary provisions for employee protection such as preferred methods for controlling exposure, respiratory protection.
When overburning occurs (above 700[degrees]C), the amorphous Si[O.sub.2] will be changed to cristoballite, quartz and tridymite, and when it is burnt at low temperatures (below 500[degrees]C), much carbon will exists in the product; in either case the pozzolanic activity of RHA will be decreased greatly (Chandrasekhar et al, 2003).
The proposed 50 [micro]g/m3 PEL for quartz matches 0SHA's existing threshold for two other forms of respirable crystalline silica, cristobalite and tridymite, in general industry workplaces.
In nature, the polymorphs of silica are quartz; Cristobalite; Tridymite, Coesite; Stishovite; lechatelerite and opal [15].
By contrast, the sites that become [STH.sub.2] s upon hole trapping are likely to be relatively rare, since these precursor sites have been shown [15, 16] to have [alpha]-quartz-like local structure, whereas a comparison of X-ray-diffraction radial-distribution functions of glassy silica with those the [alpha] quartz, cristobalite, and tridymite crystalline polymorphs of Si[O.sub.2] has shown quartz to be the least similar to structure to silica glass (correlation coefficient of only 0.26, versus 0.69 and 0.82 for cristobalite and tridymite, respectively [34]).
This line has the best correlation with two strong lines reported for tridymite. These lines are centered around 320 [cm.sup.-1] and 355 [cm.sup.-1] [13].
X-ray diffraction (XRD) analysis was conducted by the same independent laboratory on the grab samples to quantify the quartz, cristobalite and tridymite found in the rock dust.
Reduced Si activity was also revealed by the absence of Si[O.sub.2] polymorphs such as crystoballite, tridymite and opal in the association and because most Na zeolites formed with relatively low Si/Al ratios compared to Ca zeolites.
A medium peak centered at 21.70[degrees] (d=4.10[Angstrom]) is predominant and is very close to one of the peak of tridymite [6].
Tridymite has been reported from the Erongo Volcanic Complex (Pirajno, 1990).
Smith, D.K.: 1998, Opal, cristobalite and tridymite: non-crystallinity versus crystallinity; nomenclature of the silica minerals and bibliography, Powder Diffraction, v.