Petrichor

Origin

Released from dry soils and porous rocks like limestone and terracotta when rain falls after a period of drought, especially in warm climates. The aroma arises from plant oils absorbed by the ground combined with geosmin produced by soil-dwelling actinobacteria.

The smell

The mineral, earthy breath that rises when first rain strikes dry ground, cool and grey and impossibly fresh. It carries a dusty sweetness, the smell of wetted stone and awakened soil, with a faint metallic tang and a green undertone of released plant oils. It is nostalgia made olfactory, the scent of relief after long heat.

Key quality

The evocative scent of rain meeting parched earth, a study in mineral freshness.

Historical use

The term was coined in 1964 by Australian scientists Isabel Joy Bear and Richard Thomas from the Greek 'petra' (stone) and 'ichor' (the fluid of the gods). In India, the scent has long been captured as 'mitti attar', a perfume distilled from baked clay over sandalwood oil to bottle the smell of the first monsoon rains.