February 4, 2025, Manila- There are two kinds of igneous rock, based on where they are formed. Intrusive igneous rock is the result of magma solidifying beneath the Earth’s surface. Granite is the most common of these rocks. Peridotite is among the most striking of them. Extrusive igneous rock is the result of lava cooling and solidifying on the surface of the Earth. This can be either mafic (darker, more solid) or felsic (generally lighter, with more silica content). Basalt is a common mafic extrusive igneous rock. Pumice and rhyolite are felsic extrusives. This is some of what I learned about igneous rock, on the Fifth Floor of the Philippine National Museum of Natural History. The geology section provides a wealth of information about sedimentary and metamorphic rock, as well.

There are parallels between the two types of igneous rock and the manner in which policies are established, as well as modified, in the course of civic affairs. “Intrusive” policy change is done quietly, behind closed doors, and is pretty much solidified by the time it comes to the attention of the public-at-large. It is solid, and rather hard to modify, once it has seen the light of day. “Extrusive” policy change is effected with great fanfare, in broad daylight, and while there is a rhythm to its flow, the edges of the policy, its short-term effect on those in its path, can be quite rough. There is a reason why basalt, an extrusive igneous rock, is favoured in fashioning arrow heads. Conversely, pumice, also extrusive igneous, is well-liked as an abrasive.

These analogies came to me, as I rode the Light Rail from the museum back to Ola Hostel’s neighbourhood, this evening.