https://cdn.earthdata.nasa.gov/conduit/upload/5182/KeywordsCommunityGuide_Baseline_v1_SIGNED_FINAL.pdf 24.4 2026-07-22T11:07:16.739Z https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/instruments/4830f3e8-b4f3-4574-88d0-b52a27d52eff HPGE Germanium is a lot like silicon: It's a semiconductor from whichyou can build complex electronic circuits, and in bulk form it'sa dark, shiny crystalline yet sort of metallic solid. It's quiteexpensive, much more expensive than silicon, and not nearly ascommonly used.Germanium can also be used as an x-ray lens, because even thoughit's opaque to visible light, it transmits and can focus x-rays.Silicon and Germanium are available in higher purity grades thanvirtually any other elements. Silicon in particular can be hadin large quantities at reasonable prices, at a purity thatexceeds anything else achieved by the hand of man. Germanium issimilar, just more expensive. The reason for this is not thatother elements are necessarily more difficult to purify (someare, some aren't), it's that there is a huge market demand forhyperpure silicon and to a lesser extent germanium for thesemiconductor industry.Additional information available at'http://www.theodoregray.com/PeriodicTable/Elements/032/'