Sometimes these types of heat sinks are referred to as a HSF, which is short for heat sink and fan. Passive heat sinks are 100% reliable, as they have no mechanical components. Passive heat sinks are made of an aluminum-finned radiator that dissipates heat through convection.
Schist is a metamorphic rock that contains flakes of mica. Schist can originate as a sedimentary rock or igneous rock. <a href=http://www.softschools.com/facts/geology/schist_rock_facts/387/>Schist Rock Facts</a>. Handwriting.
This mica mineral forms shiny, flexible flakes of a deep black or brownish-black color. Large book crystals occur in pegmatites and it is widespread in other igneous and metamorphic rocks; tiny detrital flakes may be found in dark sandstones. Luster glassy to pearly; hardness 2.5 to 3.