Name: Hornblende

Locality: Tatunshan Area, northern Taiwan

Size & weight: 2.45g

Chemical Class: Silicates

Chemical Formula:

(Ca,Fe,Al)₅Si₆(Si,Al)₂O₂₂(OH)₂

Crystal System: Monoclinic system

Hardness: 5.0- 6.0

Fracture: Uneven

Cleavage: Good

Streak: Greenish gray or brownish gray or white

Common Appearance: Prismatic crystal

Luster: Vitreous luster

Color: Dark green, dark brown to black

Specific Gravity: 3.0-3.4

Hornblende is an important rock-forming mineral of wide distribution. Hornblende occurs in igneous and metamorphic rocks. Hornblende is a characteristic mineral in metamorphic rocks of intermediate grade (amphibolite).