Left, Ngipin Ng Kidlat from Siquijor, harvested from limestone. Limestone is indigenous to islands in the Visayas. It is found not only underwater, but also aboveground.  

Right, Pangil Ng Kidl;at from Calabarzon, a pair typically held in two hands. I brought these only once on travel and afterward never again--they show up in airport X-rays as solid, very black, and made of indeterminate material.

It is said of both versions that when lightning strikes a rock or a tree, these fang-like objects can be found within.

Perhaps the most popular user of Pangil Ng Kidlat (not to be confused with the black, meteor-like Mutya Ng Kidlat) was the legendary Nardong Putik, who wielded them like wands.