Zircon crystals showing partial tetragonal crystal habits from Brazil, they exhibit a vitreous lustre and have a brown colouration. Zircon is a common accessory mineral found at the earths crust, generally in igneous and metamorphic rocks or as minute grains within sedimentary rocks. It is a mineral which is very resistant to heat and erosion leading to its common occurrence on the earths surface.Although it can be found in many colours, with gem quality specimens being translucent, these particular specimens are a brown colour yet still have a vitreous lustre to them, making them glean in the light. The mineral has many uses in industry, including the casting of nuclear fuel rods, fuel converters and of course in jewellery (zirconia). These particular specimens from Brazil also have fluorescent properties, when exposed to shortwave UV light, they fluoresce a vivid yellow colour. Making these mineral samples suitable for educational use and for collectors, they range in size between 1 to 2 cm and will come supplied in a polythene bag with an information label.
Note, the image was taken using a standard digital camera in the dark and with an 8 watt mains powered shortwave uv lamp.