Heamatite in quartz

A white-ish brownish-beige stone fragment with a dark streak running through it
Haematite streak inside quartz boulder

I love haematite (also spelled hematite). This iron oxide mineral is the original mirror, having a highly polishable metallic lustre (while also dull and earthy in rough form), usually greyish-brown to silverish-grey to nearly black, and an inner core of blood red, hence the name. Haematite crystallises in the trigonal crystal system, the same as quartz, and in all sorts of habits from botryoidal to platy roses to masses to incredible hexagonal prismatic crystals.

A favourite pastime when the weather allows is fossicking for interesting crystals on the beach. Most of the time they are water-worn pebbles such as rock crystal or all manner of jaspers, banded agates and chalcedonies.

A couple of seasons ago I found this rather large quartz boulder, about the size of a football and seeming to ooze out were the blood-red or rust-like streaks. On the surface of the boulder you could clearly see a honeycomb of six-sided terminations of quartz crystals growing inside – like a geode. I couldn’t resist and although I rarely do this, I split the boulder on the beach to investigate the red streaks. It was haematite.

In the images of the hematite-carrying fragments you can clearly see its colours go from nearly black to crimson. Quartz is quite hard at 7 on the Moh’s scale while haematite is about 6. It meant the fresh edges of the split boulder were quite sharp and I left most of it on the beach to return to the ocean. I kept one of the fragments seen in these images.

A true object lesson in crystallisation and mineralisation. It felt like a message sent from the centre of the Earth.

Find out more on Minerals.net

A quartz boulder with haematite found on a south Cornwall beach (credit: Tehmina Goskar)