Sea salt forming pyramids

[fluxaphonic3]

The photos are here... http://flickr.com/photos/21905863@N06/

 

I use sea salt for cooking and have noticed since I transferred the salt to a glass jar, it has grown pyramids..

 

Being a mineral, I know that salt forms crystals, but why in this particular shape?

 

Anyone?

[chemkid]

I don't know much about the subject, but I'll give it a shot.

 

Bismuth forms rhombohedral crystals and also forms into pyramid like structures, ( Google bismuth crystals). NaCl has a cubic, very similar to rhombohedral crystal structure and might form similar crystals.

 

Could you post specifics on how you created the salt pyramids (i have made normal sat crystals in eighthth grade chem, but never pyramids)?

 

Chemkid