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

Soviet Union postage stamp commemorating Nikolay Nikolaevich Zinin (1812-1880), a Russian organic chemist who created a base of aniline, which he named benzidam.

Stamps depict Pierre and Marie Curie and are from a series put out by the Afghan Red Crescent Society.

Stamp commemorating the 2nd International Pharmacological Congress in Prague, Czech Republic.

Stamps depict Niels Bohr, the equation for the Bohr frequency condition (an equation relating to light frequency and electrons), and a diagram of the Bohr model of a hydrogen atom.

Cachet and stamp depict a mushroom cloud from a nuclear weapons test. Cachet was created by Fleetwood and the stamp was commissioned by the United Nations Postal Administration. Postmark depicts the United Nations…

Depicts Abū Bakr Muhammad ibn Zakariyyā al-Rāzī (also known as Rhazes), a Persian polymath, physician, alchemist, and philosopher.

Romanian stamp commemorating geologist Gheorghe Munteanu Murgoci (1872-1925) and the International Congress of Soil Science.

1964 German stamp commemorating the 100 year anniversary of the discovery of Benzene. The stamp depicts the Kekulé structure of benzene, which was first created by August Kekulé (1829-1896) in 1865.

Depicts Albert Einstein with his formula for special relativity, along with a rocket. Stamp was part of a series that also included Newton, Copernicus, and Galileo.

Mexican postage stamp commemorating the 200th anniversary of the birth of Spanish-Mexican scientist, engineer, and naturalist Andrés Manuel del Río (1764-1849) best known for his discovery of compounds of vanadium in…

Stamp issued to publicize the 20th Congress of the International Union of Pure and Applied Chemistry (IUPAC), held in Moscow, July 12-18. The names of both the organization and the host city are spelled with chemical…

Cachet and stamp depict Albert Einstein. Cachet also depicts Einstein's formula for mass-energy equivalence and is from the Prominent Americans Series. The postmark is from Princeton, New Jersey.

Stamp issued by the Yemen Arab Republic depicting Persian polymath Avicenna (circa 980 - 1037), also known as Ibn Sina, Abu Ali Sina, and Pur Sina, as well as red roses and the new World Health Organization headquarters…

Friedrich August Kekule von Stradonitz (1829-1896) was a German organic and theoretical chemist, whose most famous work was determining the structure of benzene. This Stamp features Kekule framed by the chemical…

Pakistani stamp commemorating "Health from herbs" and the contributions of Avicenna (980-1037), also known as Ibn Sina, a philosopher and alchemist.

Friedrich August Kekule von Stradonitz was a German organic and theoretical chemist, whose most famous work was determining the structure of benzene. The FDC features Kekule on the cachet, a postmark depicting the…

Cachet and purple stamp depict a statue of Marie Curie, while the red stamp depicts Curie herself.

Depicts oil derrick, pipeline, and emblem of the 6th Annual Arab Petroleum Congress held in Baghdad, Iraq in March 1967.

Depicts Enrico Fermi with nuclear test pile (reactor).

Japanese postage stamp commemorating the seventh International Congress of Biochemistry.

Mexican postage stamp celebrating the 7th World Petroleum Congress, which was held in Mexico City from April 2-9, 1967. The stamp features an illustrated depiction of an oil refinery.

Stamp from the German Democratic Republic (DDR) commemorating Marie Skłodowska Curie (1867-1934), a Polish-French physicist and chemist who pioneered radioactivity research and who discovered the elements polonium and…

Stamp depicts a profile of Marie Curie along with various scientific instruments.

Depicts Wilhelm Conrad Röntgen, awarded the first Nobel Prize in Physics for the discovery of X-rays, along with an X-ray tube and an atom.