Cachet and stamp depict Claude-Louis Berthollet. Cachet includes text describing Berthollet's contributions to water purification.

Stamp printed in Belgium shows the Atomium and exposition emblem of the 1958 World's Fair in Brussels.

First Day Cover with printed cachet and stamp. Cachet depicts the Atomium monument from the 1958 World's Fair Exhibition in Brussel's Belgium. Designed by engineer André Waterkeyn (1917-2005) and architects André…

Philatelic First Day Cover with printed cachet and stamp. Cachet depicts the Atomium monument from the 1958 World's Fair Exhibition in Brussel's Belgium. Designed by engineer André Waterkeyn (1917-2005) and architects…

Mexican postage stamp issued to commemorate the 20th anniversary of the nationalization of all petroleum reserves, facilities, and foreign oil companies in Mexico and the establishment of the state-owned petroleum…

Mexican postage stamp issued to commemorate the 20th anniversary of the nationalization of all petroleum reserves, facilities, and foreign oil companies in Mexico and the establishment of the state-owned petroleum…

Mexican postage stamp issued to commemorate the 20th anniversary of the nationalization of all petroleum reserves, facilities, and foreign oil companies in Mexico and the establishment of the state-owned petroleum…

Mexican postage stamp issued to commemorate the 20th anniversary of the nationalization of all petroleum reserves, facilities, and foreign oil companies in Mexico and the establishment of the state-owned petroleum…

Peruvian postage stamp commemorating the centenary of the birth of Daniel Alcides Carrión García (1857-1885), a Peruvian medical student after whom Carrion's disease is named. The stamp depicts Saint Martin de Porres…

Postcard depicting the Atomium monument from the 1958 World's Fair exhibition in Brussels, Belgium. Designed by engineer André Waterkeyn (1917-2005) and architects André (1914-1988) and Jean Polak (1920-2012), the…

Depicts three 19th-century silver miners.

Cachet and stamp depict the Swedish chemist and physicist Svante Arrhenius.

First day cover commemorating the 175th anniversary of École des Mines de Paris (National Superior School of Mines), also known as Mines Paris.

Cachet and stamp depict oil pipeline and drilling derricks.

Stamp depicts measuring instruments.

Romanian postage stamp issued in 1960 featuring an illustration of a nuclear reactor.

Cachet and stamp depict Johan Gadolin, who discovered the element yttrium and is considered the "founder of Finnish chemistry." The stamp commemorates the bicentennial of Gadolin's birth and features his likeness based…

Soviet Union postage stamp commemorating the First Congress of the International Federation of Automatic Control (IFAC), which first took place in Moscow, Russia. The stamp features the Tower of the University of Moscow…

First Day Cover commemorating the inauguration of the atomic reactor at National Tsing Hua University in Hsinchu, Taiwan. The stamp and envelope feature several illustrations of the reactor, which was completed on April…

Stamp from the inauguration of Democritus Nuclear Research Centre in Agia Paraskevi. Depicts ancient Greek philosopher Democritus and a model of an atom.

Stamp depicts chemical glassware, electron microscope, molecule, and microscopic view of cell.

Cachet depicts Alfred Nobel, while stamps depict the 1901 Nobel Prize winners.

Cuban postage stamp printed to promote world anti-malaria campaign. Depicts a chinchona plant and chemical formulas for chloroquine and primaquine, medications used to treat malaria.

Cachet and stamps depict Nobel Prize winners from 1902.

Depicts logo of the Accra Assembly held in Ghana on June 21-28, 1962, together with three postage stamps of Ghana.