K
It is the abbreviation of karat.

Kaolin
It is a group of pale colored clay minerals. In the United Kingdom, it is an industrial mineral extracted from kaolinised granites in south-west England. It is used as a pepper filler and coater, and for the higher grade ceramics and pottery (China clay).

Kaolinite
It is a hydrous aluminum silicate mineral.

Karat
It is the unit of measurement of the gold content in an ornament. Pure gold is always 24 carat. Since pure gold bends very easily, it is mixed with some tougher metals and then made into ornaments. the karat measurement determines the percentage of gold in the onnament. The scale of karat is from 1 to 24. Take for example of 14 karat gold. This mean that gold is only 14/24 i.e. 58.33%. Do not get confused with the term carat. It is the weight measurement for gemstones. The abbreviation of karat is k. or kt.

Kt
It is the abbreviation of karat.

Kerf
It is term given to a slot at the edge of a stone made with saw blade for the insertion of anchors.

Key block
It is the name given to the the first block removed from a new ledge while deepening a quarry or starting to quarry downward from a horizontal surface. It further provides space and access for removal of block by undercutting, underdrilling or lateral shifting.

Keystone
It is term used for the last wedge-shaped stone placed in the crown of an arch which is regarded as binding the whole.

Kiln
It is furnace or oven or any heated enclosure which is used for the burning of firing brick or clay material.

Kiln run
It is a term for those bricks from one kiln which have not been yet sorted or graded for size or color variation.

King closure
It is term used for a brick which is cut diagonally to have one or two inch end and one full width end.

Kneeler
It is a gabled cope stone that is also part of the wall by its shape and simultaneously may support other cope stones.