Glossary

The glossary includes and explains all technical terms used in descriptions of various items.

Automorph : Mineral whose faces are expressed. Often the term "crystallized" is used instead, it is not suitable, because all minerals are crystallized...

UV Fluorescence : Light emission caused by excitation of the material subjected to ultra-violet radiation. To highlight this phenomenon we used UV lamps, there are 2 types: short-wave and long wave. The fluorescence colors vary depending on the wavelength and the mineral species. Photo is an autunite specimen from France under long-wave UV light...

Pleochroism : Color changement of certain minerals function of their directions in polarized light. To highlight and appreciate this phenomenon must be a source of polarized light that can be achieved simply with several methods. The easiest way it's with an LCD screen (your computer for example), and to display white (by opening a blank document wordpad, paint, etc. ...). By placing the crystal in front of your screen and turning it you contemplate the pleochroism of the crystal! The second method described here requires the use of a polarizing filter (camera for example). Place the filter in front of your light source and rotate the crystal to the filter to observe the pleochroism!