Cleavage Collection - Cleavage is the tendency of minerals to break along preferred directions. Cleavage in four directions is octahedral and in six directions is dodecahedreal . This kit demonstrates 5 of these types. Fracture Collection - Fracture represents a mineral break other than along a cleavage or parting plane. Breaks may occure in any direction but are usually around some imperfection in the mineral.
Most minerals show an uneven fracture.
A few have conchoidal fractures. Native elements like copper show a hackly fracture. This kit demonstrates 5 of these types. Tenacity Collection - Various terms such as brittleness, elasticity, flexibility, malleability and sectility are used to describe the particular property of some minerals. This kit contains eight mineral specimens and a streak plate for testing color and streak.