Cannonite was named for B.B. Cannon, who first recognized the mineral. 7 and 8, p.845. It forms in vugs with pyrite an other sulfide material of complex composition. Fangite exhibits a deep-red to maroon color, and although no streak was obtained from natural fangite, synthetic fangite has an orange streak. Fangite is translucent but tarnishes to a nearly metallic luster.
Crystals have relatively flat surfaces and conchoidal fracture.
Associated minerals include realgar, orpiment, pyrite, and other sulfides. Fangite was named for Jen-Ho Fang in honor of his numerous contributions to crystallography, crystal chemistry, and geostatistics. 9 and 10, p. 1096. It is found in vuggy masses of barite, in barite and calcite veins, and in the silty, carbonaceous limestone host. Gillulyite has a deep-red color and a red streak.