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.
Any of a group of aluminum silicate minerals that can be split easily into thin, partly transparent sheets. Mica is common in igneous and metamorphic rocks. It is highly resistant to heat and is used in electric fuses and other electrical equipment.