1 Dehydration. 2  Not staying hydrated with enough water during the day may be one of the big causes of leg cramps at night. 3  This is most likely due to fluid imbalances of electrolytes (mainly sodium, potassium, calcium, and magnesium).4  Overuse of the muscles, perhaps from exercising, gardening or other physical activities. Dehydration. 2  Not staying hydrated with enough water during the day may be one of the big causes of leg cramps at night. 3  This is most likely due to fluid imbalances of electrolytes (mainly sodium, potassium, calcium, and magnesium).
Lustre (mineralogy) Lustre or luster is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the latin lux, meaning light, and generally implies radiance, gloss, or brilliance. A range of terms are used to describe lustre, such as earthy, metallic, greasy, and silky. Similarly, the term vitreous (derived from the Latin for glass, vitrum) refers to a glassy lustre. A list of these terms is given below. Lustre varies over a wide continuum, and so there are no rigid boundaries between the different types of lustre.
It is often useful to first determine if a mineral has a metallic luster. A metallic luster means shiny like polished metal. For example cleaned polished pieces of chrome, steel, titanium, copper, and brass all exhibit metallic luster as do many other minerals.