Slaggy

1834, Robert Allan, Abstract of a Paper accompanying a Suite of Volcanic Rocks from the Lipari Islands, Transactions of the Royal Society of Edinburgh, Volume 12, 531, Some portions of this obsidian are less compact, and in No, 2. we remark indications of a more slaggy structure, with several white veins intersecting the black surface in a very beautiful manner.

1949, Council of Scientific and Industrial Research (N.Z.), New Zealand Journal of Science and Technology: General Research Section, Volume 31, unidentified page, In the more slaggy parts of the sheet pale yellowish natural porcelain is found both fused to blocks of basalt and as large lumps in the filling.

1983, John P. Lehman, North Atlantic Treaty Organization Committee on the Challenges of Modern Society, Hazardous Waste Disposal, page 183, Because of the generally higher process temperature (~l.000°C versus ~800 °C ) and the more homogeneous nature of the input, the residues appear to be more slaggy or sintered.

From here to the summit the slope steepens to an angle of 20° to 30°, and the rock becomes harder and more slaggy.

Since all have been exposed by the stripping of less resistant basalt, it is worth noting that much of the Black Cuillin is still basalt because the plutonic rocks were intruded by sheets and dykes of lava, which given such cover had become tougher than the slaggier plateau basalt.

2005, Maria Beaumont, MissFit, Arrow Books, UK, page 175, This evening I′ve been the cheapest, slaggiest slag ever.