Physical Properties
Twinning in alstonite is ubiquitous, forming pseudohexagonal groups. The mineral has one imperfect cleavage and it breaks with an uneven fracture. It is not very hard, with a Mohs hardness of just 4 to 4½, a little harder than fluorite, and its specific gravity is 3.70. It is soluble in dilute HCl and it is not radioactive. The trimorphs alstonite, paralstonite and barytocalcite all have similar physical properties.
Read more about this topic: Alstonite
Famous quotes containing the words physical and/or properties:
“My vocabulary dwells deep in my mind and needs paper to wriggle out into the physical zone. Spontaneous eloquence seems to me a miracle. I have rewritten—often several times—every word I have ever published. My pencils outlast their erasers.”
—Vladimir Nabokov (1899–1977)
“A drop of water has the properties of the sea, but cannot exhibit a storm. There is beauty of a concert, as well as of a flute; strength of a host, as well as of a hero.”
—Ralph Waldo Emerson (1803–1882)