Quartz, Calcite and Bornite

Sample of long thin prismatic euhedral Quartz crystals that are colourless and have a vitreous lustre. Crystals are terminated by double rhombohedron. Compact/oolitic white Calcite with a vitreous lustre. A few deep-blue euhedral dodecahedral Bornite with a metallic lustre. Quartz (SiO2) can come in variety of colours from white to purple. Lustre vitreous or greasy and streak is white. Hardness is 7. Quartz can be long or short prismatic crystals that are terminated by double rhombohedrons. Quartz can also be granular, massive or disseminated. Calcite (CaCO3) is white, colourless or pale shades of grey, yellow, red, green or blue but can be brown or black with impurities. Lustre is vitreous or dull and streak is white. Hardness is 3 and cleavage is perfect in three directions, forming a rhombohedron. Calcite usually occurs as rhombohedron or scalenohedron but can also be prismatic, tabular, acicular, cleavable, granular, compact or earthy in form. Bornite (Cu5FeS4) can be copper-red to bronze-brown that tends to be tarnished deep blue, purple or variegated. Lustre is metallic and streak is greyish black. Hardness is 3. Bornite crystals are rare but can be cubic, dodecahedral and octahedral. Usually occurs as compact and granular. Known as "Peacock Mineral".