Meaning & symbolism
Prehnite is a pale apple-green to yellow-green calcium aluminium silicate that grows in botryoidal masses, meaning rounded bunched surfaces like a cluster of grapes, built from tightly packed fibres radiating outward from many centres. That internal fibre structure is why polished prehnite glows softly from within rather than being clear like glass. It forms at low temperature in gas cavities in basalt alongside zeolites and calcite, and during very mild metamorphism, so much so that geologists named a band of the metamorphic map after it: the prehnite-pumpellyite facies, roughly 250 to 350 degrees Celsius. Named in 1788 by Abraham Gottlob Werner after Colonel Hendrik von Prehn (1733-1785), who brought the first specimens back from the Cape of Good Hope, it is generally held to be the first mineral species ever named after a person.
Healing properties
How to use it
Keep it where the small unfinished things pile up: a desk, a hallway shelf, a bag pocket. Hold it when you are trying to tell a genuine hunch from anxious noise, since tradition gives prehnite the quiet second voice rather than the loud first one. It suits the beginning of things, so it travels well into a new job or a new home. As a pendant or earrings it outlasts a ring, which meets doorframes.
Cleansing & care
Prehnite is an insoluble silicate, so water does it no harm: a rinse in cool water with a soft cloth is fine, despite the common advice to keep water contact brief. The real risk is mechanical. At 6 to 6.5 on the Mohs scale it resists scratching reasonably well, but it is brittle and has one good cleavage plane, so it chips and can split cleanly on a hard knock. Store it apart from quartz, topaz and harder stones, give it its own soft pouch, and never put it in an ultrasonic cleaner. Running water or a night in moonlight both suit it for cleansing.
Questions & answers
PRAY-nite. The h is silent, because Prehn is a Dutch surname rather than an English word.
