Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)

“Pantsir-S1 (NATO reporting name SA-22 Greyhound) is a combined short to medium range surface-to-air missile and anti-aircraft artillery weapon system produced by KBP of Tula, Russia. The system is a further development of SA-19/SA-N-11 and represents the latest air defence technology by using phased-array radars for both target acquisition and tracking”. – Wikipedia

Photo: Test of the surface-to-air missile Pantsir-S rocket and gun system in the conditions of the Polar region on the range “Pemba” near Vorkuta, approximately on October 20 2012. According to the statement of military, during doctrines five cruise missiles from five were destroyed. (Photo by Alexey Reznichenko)

Swimmers known as the Lido Ladies pose by the pool during sunrise at Charlton Lido in Hornfair Park, London on December 2, 2020, on its first day of reopening after the second national lockdown ended and England enters a strengthened tiered system of regional coronavirus restrictions. (Photo by Victoria Jones/PA Images via Getty Images)

The mineral pyrite, or iron pyrite, also known as fool's gold, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold. The color has also led to the nicknames brass, brazzle, and Brazil, primarily used to refer to pyrite found in coal.
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals.

“The Boeing X-45 unmanned combat air vehicle is a concept demonstrator for a next generation of completely autonomous military aircraft, developed by Boeing's Phantom Works. Manufactured by Boeing Integrated Defense Systems, the X-45 was a part of DARPA's J-UCAS project”. – Wikipedia

Photo: Two X-45A Unmanned Combat Air Vehicles (UCAV) are shown to members of the news media July 11, 2002 at Edwards Air Force Base, California. The X-45A, developed by The Defense Advanced Research Projects Agency and the Boeing Company, is the first unmanned system designed from inception for combat missions. (Photo by David McNew/Getty Images)

Russian servicemen stand next to a Russian Yars RS-24 intercontinental ballistic missile system before a rehearsal for the Victory Day parade, with the Moscow International Business Center also known as “Moskva-City” seen in the background, at a range in Moscow, Russia, May 5, 2016. (Photo by Maxim Shemetov/Reuters)