any of a group of rock-forming minerals, as hornblende or actinolite, composed largely of silica, calcium, iron, and magnesium: they are common constituents of igneous and metamorphic rocks
Origin of amphiboleFrench from Late Latin amphibolus, ambiguous from Classical Greek amphibolos from amphiballein, to throw around, doubt from amphi-, amphi- + ballein, to throw: see ball
Any of a large group of structurally similar silicate minerals, such as hornblende, that have a crystalline structure consisting of a double chain of linked SiO4 units and that contain various combinations of sodium, calcium, magnesium, iron, and aluminum. Several varieties of asbestos are fibrous forms of amphiboles.
Origin of amphiboleFrench from Late Latin amphibolus ambiguous from Greek amphibolos doubtful from amphiballein to throw on either side amphi- amphi- ballein to throw ; see gwelə- in Indo-European roots.