277. Sn occurs as the mineral cassiterite, tin stone, Sn02, and is found in only a few localities, as Banca, Malacca, and England.
"An Introduction to Chemical Science"
R.P. Williams
All these minerals are relatively insoluble and have high specific gravity, and as a consequence they are frequently accumulated in placers, along with cassiterite and other stable, heavy minerals.
"The Economic Aspect of Geology"
C. K. Leith
The solutions which deposited the ores are inferred to have been hot from the nature of the wall-rock alterations, from the presence of hot-water minerals like fluorite, cassiterite, and others, and from the general association of the ores in time and place with the porphyry intrusions.
"The Economic Aspect of Geology"
C. K. Leith