Porphyry is a volcanic rock. The porphyry stone is the result of a long and intense volcanic activity, that began 260 millions of years ago and which continued for several millions of years by alternating eruptive and standstill phases.
Most lack access to clean water, energy, and health services, either because the costs of extending these services are high; the motivation to do so is low, or both. As such, rural poor seeking access to these services and their accompanying opportuni ...