petrichor (n.)
Petrichor is the earthy smell associated with rain after a dry spell. The word joins Greek petra, stone, with ichor, the fluid said to flow in the veins of the gods.1
The name appeared in a 1964 paper by Isabel Joy Bear and Richard Thomas, researchers at Australia’s CSIRO. Their article, Nature of Argillaceous Odour, was published in Nature on March 7.2
They had been investigating a smell familiar to people long before it had this scientific name. Indian perfumers had already captured an earthy scent in sandalwood oil. Bear and Thomas approached it through mineral chemistry. By steam-distilling rocks that had been exposed to warm, dry conditions, they obtained a yellowish oil associated with the odor. Moisture helped release it from the materials that held it.1
Petrichor drifted through the open window when the rain began.