petrichorn.

1964 I. J. Bear & R. G. Thomas in Nature 7 Mar. 993/2 The diverse nature of the host materials has led us to propose the name ‘petrichor’ for this apparently unique odour which can be regarded as an ‘ichor’ or ‘tenuous essence’ derived from rock or stone. This name, unlike the general term ‘argillaceous odour’, avoids the unwarranted implication that the phenomenon is restricted to clays or argillaceous materials; it does not imply that petrichor is necessarily a fixed chemical entity but rather it denotes an integral odour.

1971 Listener 4 Nov. 612/3 No matter what kind of rock or earth was used, the oily essence always possessed the aroma of petrichor—the smell of rain falling on dry ground.

1975 Sunday Mail (Brisbane) 2 Nov. 32/2 The globules, nicknamed ‘petrichor’ or ‘essence of rock’ by the researchers, contained at least 50 different compounds, not unlike a perfume and were absorbed into the ground from the air.

1993 Canad. Geographic Sept. 13/1 Petrichor comes from atmospheric haze, which contains the terpenes, creosotes and other volatile compounds that emanate from plants.

1998 L. Forbes Bombay Ice (1999) 11 First there is petrichor, the dry smell of unbaked clay, from the Greek for ‘stone-essence’.