Mineral Structure - Cleavage and Fracture Experimental Kit

Excellent activity to follow study of crystal structure, students identify minerals by physical properties of cleavage and fracture. Included are samples which show cleavage in 1, 2, 3, 4 and 6 directions, and exhibit conchoidal and uneven fracture. Students use a goniometer to study cleavage direction and relate properties of the minerals to their commercial uses. Kits contains five specimens each of: biotite mica, calcite, fluorite, halite, hornblende, microcline feldspar and sphalerite; eight specimens each of: obsidian, serpentine; 15 contact goniometers; and 30 student worksheets. Comes with teacher's instruction booklet providing full background information and materials for 30 students.