Do you know? Have you seen,?

[Johnnyrockit]

Have you seen such minerals?

 

[ticndig]

I'm not a rock expert, my guess is they were cut like that to use as property markers. I've seen stone markers at old home sites

 

[Argentium]

Welcome to T-net Johnny ! That's quite a cluster
of crystals !! I think if you scroll down the Forum
page you'll find a sub forum dedicated more to gems and minerals - that might get your answers pretty quick . It is fascinating to realise that all crystals conform to one of only six crystal systems ! So someone will see it and get back to
you .

 

[A2coins]

Welcome to tnet yep try rock and gem forum. Interesting for sure

 

[Westfront]

Looks like basalt/tap rock/green rock to me. Volcanic rock. We call it pillar basalt.

source wikipedia

 

[Jason in Enid]

Westfront called it right. They are Basalt pillars. They form from the crystalized magma in a volcano core. There are many examples around the world. The "devil's tower" in Wyoming is on well known formation.

 

[Ponchosportal]

Columnar jointing is a geological structure where sets of intersecting closely spaced fractures, referred to as joints, result in the formation of a regular array of polygonal prisms, or columns. Columnar jointing occurs in many types of igneous rocks and forms as the rock cools and contracts.

 

[Professor of Engineering]

Awesome! I would liked to have found/recovered those beauties!

 

[1637]

look up devils postpile in ca.
brad

 

[smokeythecat]

As stated, columnar basalt.

 

[Kray Gelder]

A drive along the Columbia River in Washington State is highlighted by the basalt flows, many of them showing columnar jointing.



Over a great period of time, from about 17 million years ago up to 6 million years ago, a serious amount of lava flowed from huge fissures over what we now call the Yellowstone Hot Spot, and flooded parts of Idaho, Washington, and Oregon. The flows are up to 900 meters thick in the Clearwater region of Idaho.

This shot is along the Columbia River.



Each layer represents a separate eruption.