Crossword-Solution: CLINKSTONE 10 letters, 1 clue 🏆 scrabble score: 16

The term was subsequently made to include other rocks, such as clinkstone and obsidian, which have the same mineral composition, but to which, owing to their different texture, the word in its original meaning would not apply.

When it contains disseminated crystals of feldspar, it is called _Clinkstone porphyry._ Volcanic Rocks distinguished by special Forms of Structure.—Many volcanic rocks are commonly spoken of under names denoting structure alone, which must not be taken to imply that they are distinct rocks, i.e., that they differ from one another either in mineral or chemical composition.

These have their origin amongst the clinkstone heights of Mont Mezen, and taking their course along the granitic plateau in a south-easterly direction, ultimately pass over on to the Jurassic and Cretaceous formations composing the plateau of the Coiron, which break off in vertical cliffs from 300 to 400 feet in height, surmounting the slopes that rise from the banks of the Ardèche and Escourtais rivers near Villeneuve de Bere.

The varieties most frequently spoken of are basalt, greenstone, syenitic greenstone, clinkstone, claystone, and trachyte; while those founded chiefly on peculiarities of texture, are porphyry, amygdaloid, lava, tuff, scoriæ, and pumice.

Other minerals are occasionally found in basalt; and this rock may pass insensibly into almost every variety of trap, especially into greenstone, clinkstone, and wacké, which will be presently described.