The scoria cones that dominate the landscape in the west of the island – huge symmetrical piles of red grit such as Cross Hill, which towers almost 300 metres over Georgetown, or Command Hill, which overlooks the airbase - are steep on the windward side, less so on the lee.
Pyroclastic cones (also called cinder cones or scoria cones) such as Cerro Negro in Nicaragua are relatively small, steep (about 30°) volcanic landforms built of loose pyroclastic fragments, most of which are cinder-sized.
Lastly, tachylytes occur as scoria, or bombs, thrown out by basaltic volcanoes; these are well known at Stromboli Island and at Mount Etna in Italy, and in Iceland.
Foamlike scoria, in which the bubbles are very thin shells of solidified basaltic magma, occurs as a product of explosive eruptions (as on Hawaii) and as frothy crusts on some pahoehoe (smooth- or billowy-surfaced) lavas.
From the moon-like red summit textured in black scoria and dust, where almost nothing could grow, I passed through a sea of clouds to the laurisilva forest, dripping in lichen and ferns and with tangled tree limbs clambering for light.
Other scoria, sometimes called volcanic cinder, resembles clinkers, or cinders from a coal furnace.
Wells being hydraulically fractured were ringed by 20 or more water tanks spread out on square mounds of brick-red "scoria" — a clay sintered by underground coal fires and used for drill pads and roads in North Dakota.
One of them, "Double Navel," a detail of a rock that has the same contours as a human torso, comes in close on the gashes, holes, and scoria of a rock's surface, and the analogy White was making with the wounds of war is hard to miss.
The X-ray fluorescence spectrometer provides a tool for making chemical analyses of rocks that are important for understanding the chemistry of a wide variety of volcanic products (e.g., ashes, pumice, scoriae, and bombs) and of the magmas that give rise to them.
Cinders, sometimes called scoriae, are the next in size; these coarse fragments can range from 2 mm (0.08 inch) up to about 64 mm (2.5 inches).
Exclamation points fall upon the page like, well, scoriae.
