An active vocabulary is made up of the words readily used and clearly understood by an individual when speaking and writing. Contrast with passive vocabulary. Martin Manser notes that an active vocabulary consists of the words that [people] use frequently and confidently. If someone asks them to make up a sentence containing such and such a wordâand they can do itâthen that word is part of their active vocabulary..
Roofing slate is a dense, durable, naturally occurring material that is essentially nonabsorbent. Two properties of slate are cleavage and fracture. It has natural cleavage, which permits it to be easily split in one direction.Fracture, usually occurring at right angles to the cleavage, is called the grain. Roofing slate commonly is split so the length of the slate runs in the direction of the grain.The surface texture of slate after being split for commercial use derives from the characteristics of the rock from which it was quarried.oofing slate is a dense, durable, naturally occurring material that is essentially nonabsorbent. Two properties of slate are cleavage and fracture. It has natural cleavage, which permits it to be easily split in one direction.
Foliated metamorphic rock. Foliation forms when pressure squeezes the flat or elongate minerals within a rock so they become aligned. These rocks develop a platy or sheet-like structure that reflects the direction that pressure was applied in.Slate, schist, and gneiss (pronounced 'nice') are all foliated metamorphic rocks.on-foliated metamorphic rocks do not have a platy or sheet-like structure. There are several ways that non-foliated rocks can be produced. Some rocks, such as limestone are made of minerals that are not flat or elongate. No matter how much pressure you apply, the grains will not align!