Obsidian gives conchoidal fractures

Conchoidal fracture describes the way that brittle materials break when they do not follow any natural planes of separation. Materials that break in this way include flint and other fine-grained minerals, as well as most amorphous solids, such as obsidian and other types of glass. Image File history File links Download high resolution version (870x870, 89 KB) Summary A specimen of obsidian from Lake County, Oregon Licensing File links The following pages link to this file: Obsidian ... Image File history File links Download high resolution version (870x870, 89 KB) Summary A specimen of obsidian from Lake County, Oregon Licensing File links The following pages link to this file: Obsidian ... This article is about a type of volcanic glass. ... For other uses, see Fracture (disambiguation). ... A material is brittle if it is subject to fracture when subjected to stress i. ... Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite planes, creating smooth surfaces, of which there are several named types: Basal cleavage: cleavage parallel to the base of a crystal, or to the plane of the lateral axes. ... This article is about the sedimentary rock. ... A crystallite is a domain of solid-state matter that has the same structure as a single crystal. ... For other uses, see Mineral (disambiguation). ... Wax and paraffin are amorphous. ... This article is about a type of volcanic glass. ... This article is about the material. ...

Conchoidal fractures can also occur in other material under favorable circumstances. This material property was widely used in the Stone Age to make sharp tools, and minerals that fractured in this fashion were widely traded as a desirable raw material. Stone Age fishing hook. ...

Conchoidal fractures often result in a curved breakage surface that resembles the rippling, gradual curves of a mussel shell; the word "conchoid" is derived from the word for this animal. A swelling appears at the point of impact called the bulb of percussion. Shock waves emanating outwards from this point leave their mark on the stone as ripples. Other conchoidal features include small fissures emanating from the bulb of percussion. Subclasses Pteriomorpha (marine mussels) Palaeoheterodonta (freshwater mussels) Heterodonta (zebra mussels) The term mussel is used for several families of bivalve molluscs inhabiting lakes, rivers, and creeks, as well as intertidal areas along coastlines worldwide. ... Fissure (Latin fissura, Plural fissurae) is a groove, natural division, deep furrow, or cleft found in the brain, spinal cord, and liver; or a tear in the anus. ...

They are defined in contrast to the faceted fractures often seen in single crystals such as semiconductor wafers and gemstones, and the high-energy ductile fracture surfaces desirable in most structural applications. See the main article on Fracture. Facets are flat faces on geometric shapes. ... For other uses, see Crystal (disambiguation). ... It has been suggested that Wafer prober be merged into this article or section. ... For other uses, see Gemstone (disambiguation). ... Ductility is the physical property of being capable of sustaining large plastic deformations without fracture (in metals, such as being drawn into a wire). ... For other uses, see Fracture (disambiguation). ...

Conchoidal fractures form the basis of flint knapping, since the shape of the broken surface is controlled only by the stresses applied, and not by some preferred orientation of the material. This property also makes such fractures useful in engineering, since they provide a permanent record of the stress state at the time of failure. As conchoidal fractures can be produced only by mechanical impact, rather than frost cracking for example, they can be a useful method of differentiating prehistoric stone tools from natural stones. A flintknapper is an individual who shapes flint or other stone through the process of knapping or lithic reduction no shit sherlock, to manufacture stone tools, strikers for flintlock firearms, or to produce flat-faced stones for building or facing walls. ... Stress is a measure of force per unit area within a body. ... Fail and Phail redirect here. ... Frost on black pipes Frost is a solid deposition of water vapor from saturated air. ...

Conchoidal fracture in art

Conchoidal fracture in glass

Conchoidal fracture as originally developed by prehistoric men is used by highly skilled artists to craft bifacial glass pieces for ornamental, as well as functional enlightened sculptures. In the latter case, the bifacial glass piece is illuminated from its base with powerful lightning systems, hence providing a unique render of emitted light through the conchoidal fractured planes.