Containing amygdules. See Amygdule
Containing amygdules. See Amygdule
A mineral group including actinolite, anthophyllite, arfvedsonite, cummingtonite, hornblende, richterite, glaucophane, grunerite, anthophyllite, riebeckite, tremolite, and others
The gradual and systematic reduction of a balance in an account over an assigned period
Rocks or minerals lacking crystal structure or form
A variety of translucent to transparent purple to grey coloured quartz common as a semiprecious gemstone. The color results from with ferric iron substitution for silicon
The surrounding or encompassing and current state of an area
The formation of usually fossilized amorphous hydrocarbons from ancient tree resins, having highly variable C:H:O ratios
A bright green or blue green variety of microcline sometimes cut as semi precious stones and for ornamental use
Alloys of mercury with one or more metal
A light, silvery-white, ductile metal with high electrical conductivity and high resistance to oxidation. Symbol, Al