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Experimental methods for quenching structures in lunar-analog silicate melts: Variations as a function of quench media and compositionCompositions analogous to lunar green, organge, and brown glasses were synthesized under consistent conditions, then quenched into a variety of different media when the samples were removed from the furnace. Iron valence and coordination are a direct function of quench media used, spanning the range from brine/ice (most effective quench), water, butyl phthalate, silicone oil, liquid nitrogen, highly reducing CO-CO2 gas, to air (least efficient quench). In the green and brown glasses, Fe(3+) in four-fold and six-fold coordination is observed in the slowest-quenched samples; Fe(2+) coordination varies directly with quench efficiency. Less pronounced changes were observed in the Ti-rich orange glass. Therefore the remote-sensed spectrum of a glass-bearing regolith on the Moon may be influenced by the process by which the glass cooled, and extreme caution must be used when comparing spectra of synthetic glass analogs with real lunar glasses.
Document ID
Acquisition Source
Legacy CDMS
Document Type
Dyar, M. D.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Date Acquired
August 12, 2013
Publication Date
April 1, 1985
Publication Information
Publication: NASA, Washington Repts. of Planetary Geol. and Geophys. Program
Subject Category
Inorganic And Physical Chemistry
Accession Number
Distribution Limits
Work of the US Gov. Public Use Permitted.

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