Renierite

Infrared optics & fiber-optics depend on germanium crystals. Germanium is important to defense and law enforcement because of its use in technologies like infrared night vision and satellite solar cells. Most germanium production is concentrated in a few countries—Canada, China, Finland, and Russia. The United States is completely dependent on imports for its germanium consumption. Image credit: By Alchemist-hp (talk) (www.pse-mendelejew.de) - Own work, CC BY-SA 2.0 de, https://commons.wikimedia.org/w/index.php?curid=4272283