Stilbite

Cleavelandite is a variety of the mineral albite, one of the constituent minerals of plagioclase feldspar, thus is found in areas where pegmatites and granites exists in certain localities around the world. These particular specimens come from Evje, in Southern Norway and as expected, has a pale green colouration to it. As with albite, cleavelandite also exhibits a triclinic crystal habit and has a hardness of 6- 7 on the Moh’s scale of hardness, it is usually found within cavities of other rocks or minerals. It as named in 1823 by Henry J. Brooke in honor of Parker Cleaveland , professor of geology and mineralogy at Bowdoin College in Maine. Our mineral specimens are massive in form with occasional accessory such as smokey quartz or plagioclase or orthoclase feldspar. The specimens were collected by our own staff from Evje and are available in a range of sizes. Each specimen is supplied in a labelled card tray.

Chalcopyrite mineral specimens from Sulitjelma, Norway, a major copper ore mineral, these pieces exhibit excellent quality chalcopyrite detailing the shiny brassy yellow colouration and metallic lustre expected. These mineral specimens are approximately 70% – 80% chalcopyrite and are available in various sizes and come supplied in 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.