Fluorite Display Piece – 1

Iceland spar is a clear variation of calcite, it exhibits the rhombic crystal system of calcite perfectly, the crystals easily divide into rhombs, making them well sought after for a variety of reasons. Originally reported from Helgustadir Mine, Eskifjord, Iceland, hence its name. One of the most remarkable aspect of Iceland spar is its refractive properties. When light passes through one of the crystals, it is divided into two rays at different angles which results in a double refraction effect. Essentially, anything seen though the crystal is seen in double. This can best be seen if you place the calcite over some text, it will appear as if it has been printed twice. These mineral samples come from Santa Eulalia, Chihuahua, Mexico and are available in 2 sizes: Upto 1″ and Over 1″. They come in a card tray with an information label.

Chalcedony mineral specimens from Morocco, the pieces belong to the quartz family of minerals and is very similar to carnelian, even having a waxy lustre, although it tends to have a botryoidal crystal habit. The pieces are blue, white, red and orange and available in various sizes, supplied in a card tray with an information label.

Baryte (also spelt barite) is a widely occurring mineral consisting of barium sulphate, they can occur with many crystal habits, in this case, these mineral specimens exhibit the cockscomb mass form, in which randomly orientated blades of the mineral occur on a massive bed. These particular specimens are a pink or orange colour with a pink bed but other colours of baryte exists, including white, buff or brown. Any barite specimen is incredibly dense, with small pieces even feeling heavier than they appear, which is surprising, considering it is a non metallic mineral. This density was how the mineral obtained its name, being derived from the Greek word ‘βάρυζ’ meaning heavy. It occurs in a range of environments and deposited via many processes including biogenic, hydrothermal and evaporation, among others. Commonly occurring in lead-zinc veins hence some of the samples contain galena (lead sulphide) as well. Over 75% of baryte extracted worldwide is used for weighting driling fluids in oil and gas exploration to control high formation pressures and prevent blowouts. These mineral specimens were mined in Mibladen, Morocco, they are available in various sizes, each specimen is supplied in a labelled card tray.