Dry stoneDry stone, sometimes called drystack or, in Scotland, drystane, is a building method by which structures are constructed from stones without any mortar to bind them together. A certain amount of binding is obtained through the use of carefully selected interlocking stones. Dry stone construction is best known in the context of stone walls, traditionally used for the boundaries of fields and churchyards, or as retaining walls for terracing, but dry stone shelters, houses and other structures also exist.
Occupational burnoutAccording to the World Health Organization (WHO), occupational burnout is a phenomenon resulting from chronic work-related stress, with symptoms characterized by "feelings of energy depletion or exhaustion; increased mental distance from one’s job, or feelings of negativism or cynicism related to one's job; and reduced professional efficacy". While occupational burnout may influence health and can be a reason for people contacting health services, it is not itself classified by the WHO as a medical condition or mental disorder.
Dimension stoneDimension stone is natural stone or rock that has been selected and finished (e.g., trimmed, cut, drilled or ground) to specific sizes or shapes. Color, texture and pattern, and surface finish of the stone are also normal requirements. Another important selection criterion is durability: the time measure of the ability of dimension stone to endure and to maintain its essential and distinctive characteristics of strength, resistance to decay, and appearance.
Stone AgeThe Stone Age was a broad prehistoric period during which stone was widely used to make stone tools with an edge, a point, or a percussion surface. The period lasted for roughly 3.4 million years and ended between 4,000 BC and 2,000 BC, with the advent of metalworking. Though some simple metalworking of malleable metals, particularly the use of gold and copper for purposes of ornamentation, was known in the Stone Age, it is the melting and smelting of copper that marks the end of the Stone Age.