difference between amphibole and hornblende

Amphibole and hornblende are terms that are often used interchangeably, but they refer to different aspects of the same mineral group. Let’s break down the differences between the two:

Amphibole:

Amphibole is a mineral group that belongs to the larger group of inosilicates, which are minerals with a complex chain structure of silicate tetrahedra. The general formula for amphibole is (Na,K)0-1(Ca,Na,Fe,Mg)2(Mg,Fe,Al,Fe,Ti)5(Si,Al)8O22(OH,F)2. Amphibole minerals are typically black, dark green, or brown in color and have a prismatic or needle-like crystal habit.

Hornblende:

Hornblende is a specific member of the amphibole group. It is the most common and widely recognized amphibole mineral. The name “hornblende” is often used to describe dark-colored amphiboles that form elongated crystals. The term “hornblende” is frequently used in igneous and metamorphic petrology to describe the dark-colored, needle-like or bladed crystals commonly found in those rocks.

In summary, “amphibole” is the broader group that encompasses various minerals with a specific crystal structure, while “hornblende” is a specific type of amphibole mineral. The term “hornblende” is often used in a more geological context, while “amphibole” is the broader mineralogical term.