Analysis of information sources in references of the Wikipedia article "Sodium hexafluoroaluminate" in English language version.
[From p. 312] Han har kaldt denne grönlandske Steen Kryolith eller Iissteen formedelst dens Udseende, og fordi den smelter saa meget let for Blæsröret.(He has named this Greenlandic stone cryolite or ice stone on account of its appearance, and because it melts so easily under a blowpipe.)