Vasconcelles, Jesuit father, describes one which he heard in the Sierra, or mountain region of Piratininga, and which he compares to the discharges of a park of artillery.

The Indians told him that it was an explosion of stones.
The worthy father had soon a satisfactory proof of the truth of their information, for the very place was found where a rock had burst and exploded from its entrails a stony mass, like a bomb-shell, and of the size of a bull's heart.

This mass was broken either in its ejection or its fall, and wonderful was the internal organization revealed.

It had a shell harder even than iron; within which were arranged, like the seeds of a pomegranate, jewels of various colors; some transparent as crystals; others of a fine red, and others of mixed hues.

The same phenomenon is said to occur occasionally in the adjacent province of Guayra, where stones of the bigness of a man's hand are exploded, with a loud noise, from the bosom of the earth, and scatter about glittering and beautiful fragments that look like precious gems, but are of no value.
The Indians of the Orellanna, also, tell of horrible noises heard occasionally in the Paraguaxo, which they consider the throes and groans of the mountains, endeavoring to cast forth the precious stones hidden within its entrails.