Maelezo: Jiwe la volkeno linalojulikana kama pumice au basalt ya porous, ni aina ya nyenzo za kazi na za mazingira.Ina kadhaa ya madini na microelements, kama vile sodiamu, magnesiamu, alumini, silicon, kalsiamu, titanium, manganese, chuma, nickel, cobalt na molybdenum na kadhalika.

Matumizi: ujenzi, uhifadhi wa maji, kusaga, nyenzo za chujio, barbequecarbon, usanifu wa mazingira, kilimo kisicho na udongo, bidhaa za mapambo na nyanja zingine.

Rangi: nyekundu, nyeusi.nyeupe
ukubwa: 3-6mm, 6-8mm,8-10mm,1-3cm,3-6cm,6-8cm,8-10cm,10-50cm inaweza kuwa umeboreshwa.style: jiwe, chembe, poda.