Democratic Sentinel, Volume 19, Number 15, Rensselaer, Jasper County, 19 April 1895 — Rocks that Float in Water. [ARTICLE]

Rocks that Float in Water.

A geologist who is “well up” in his business can name a dozen or twenty different specimens of rocks and minerals that have less specific gravity than water, and which will, if tossed into that element, float on the surface. Hubelite is one of the best known representatives of that class; the common pumice stone is another example. The rock with the very least specific gravity known is “damarl,” a substance found in an extinct volcano in Damaraland. Its atomic weight is 0.5, or exactly one-half that of hydrogen.—St Louis Republic.