Oldoinyo Lengai Volcano (Tanzania) is the only volcano erupting silvery Carbonatite lava in historical times. Unlike normal lava, this lava looks like a silvery mud as it is too cool (550-700 deg. celsius) to glow visibly during daylight. A very weak glow can be observed at night and captured by long exposure photography (see e.g.http://www.photovolcanica.com/VolcanoInfo/Oldoinyo%20Lengai/Oldoinyo%20Lengai.html)
Currently the type of activity shown can not be viewed following larger eruptions in 2007-2008 which left a large crater and removed the small eruptive cones as seen in the footage. The footage taken in July 2000 shows an extremely active cone on the main crater floor. A brief view is taken into the tiny lava lake in the top of the cone during a phase of reduced activity and multiple overflows and resulting lava flows and other features are documented.

Source YouTube (fair use)