Calcite, CaCO3 Calcium carbonate in precipitated form. A little bit of a novelty in my collection, this specimen was first collected in liquid form, oozing out of the quarry face at Ystrad Meurig in Ceredigion. After a few months the specimen hardened as the liquid dried out, leaving calcite in an irregular form. That was back in 2005, and ever since it has hardened even more.
Spodumene ( Kunzite var. ) LiAl(SiO3)2 is a pyroxene mineral, lithium aluminium inosilicate. This specimen of the kunzite var. of spodumene displays the usual characteristics, with a very pale pink colouration, striations along it's length, and a pitted surface. The pink colour is the result of traces of manganese, and there is some iridescence at the narrow end of the crystal. Spodumene is a main source of lithium. Unfortunately the origin of the specimen is unknown.
The two main components of this specimen are almandine garnet, and muscovite mica. There is also some quartz, and dull grey/black amphiboles. The wine red garnet is massive, and only shows fractured surfaces. The muscovite mica is shiny silverish plates, with some pseudo hexagonal plates observed. This specimen should really be listed as a rock rather than a mineral. It's location is from the pegmatites of the Evje area of Norway.
Tourmaline is a crystalline boron silicate mineral. The specimen is composed of black tourmaline in massive granular form, set in granite.The structure of the crystals is not immediately obvious because of the massive nature. The inset central photograph is approx 5 mm x 5 mm and is taken from the surface of the smaller specimen. The parallel acicular crystals can be seen, but even the longest crystals are only 2 mm in length. The specimens location is only known as Cornwall.
Calcite, CaCO3 calcium carbonate. There is nothing remarkable about this specimen. It is simply a lump of massive calcite, included in this collection only because I took a fancy to it when I visited the Snailbeach mine in Shropshire, about 15 years ago. There is an enormous amount of this gangue mineral at the mine, which was the largest lead mine in Shropshire. The calcite on the waste tips is very often found in association with sphalerite. or with sphalerite inclusions. Tested with a U.V. light it fluoresces a pale red.