Fun fun fun.. I got these drop by tons, as stated by Thornesque. Since i like to tease and nobody know what this can be used for, i put one for sale in Bazaar for 900k :o) (yes, 900.000 pp). Needless to say i never sold any :oP Now, it's not uncommon on RN to see some for sale in Bazaar for insane ammounts (one right now at 10k). Get a sheep to jump from a cliff and all the others will too...
Got a bunch of these while killing the Fire Elementals in Nadox. I have no idea what they are, but they sold for 20pp to the venders in PoK.
Also, a Basalt of Lava dropped from a scorned elemental. Haven't seen this anywhere as a drop. Did a search on allakhazam but it wasn't listed. Woohoo! new item find!!! I sold it to a vender for 100pp