tridymite


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Related to tridymite: cristobalite

tridymite

(ˈtrɪdɪˌmaɪt)
n
(Minerals) a form of silica found in igneous rock
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.tridymite - a mineral form of silicatridymite - a mineral form of silica    
mineral - solid homogeneous inorganic substances occurring in nature having a definite chemical composition
silica, silicon dioxide, silicon oxide - a white or colorless vitreous insoluble solid (SiO2); various forms occur widely in the earth's crust as quartz or cristobalite or tridymite or lechatelierite
References in periodicals archive ?
It exists in three distinct forms: quartz, cristobalite, and tridymite.
On Earth, tridymite is only found in environments with low pressures but extremely high temperatures--typically, explosive, silica-rich volcanic eruptions.
At another site, Curiosity found tridymite, a silicon dioxide that forms above 870[degrees] Celsius, where flows of silica-rich lava cool, says Richard Morris, a geochemist at NASA's Johnson Space Center in Houston.
The usual origin of tridymite on Earth involves high temperatures in igneous or metamorphic rocks, but the finely layered sedimentary rocks examined by Curiosity have been interpreted as lakebed deposits.
That lower level would also apply to two other forms of crystalline silica: cristobalite and tridymite.
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].