Gems and geological specimen collections can be some of the most visually striking, which is why a lot of thought has to go into lighting mineral collections. These specimens interact strongly with illumination, sparkling or shining with a lustrous glow if the fixtures are set up just right. Under poorly positioned or focused illumination, though, the specimens will appear lifeless. That is why jewelry shops keep their products in glass display cases, as this provides a frame for mounting many fixtures.
When lighting mineral collections, the major consideration is how the fixtures are positioned. Gems and rocks are adorned with many faces, and each one can shine if illuminated properly. This is why fixture designers will usually set up several small fixtures around a single subject. Each fixture will create a point of illumination on the subject’s surface.
The best way to achieve this effect is with fixtures that can be precisely aimed and focused. Fluorescent tubes, for example, emit diffused illumination that won’t create the tiny reflections a designer is aiming for. Instead, most experts rely on directional halogen fixtures, and in particular the MR-11 and MR-16 varieties. Both are built with internal reflectors that send illumination forward, and both offer several dispersion patterns. This will be extremely helpful when coming up with a tailored illumination pattern for each specimen.