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It is an igneous rock. [6] Obsidian is produced from felsic lava, rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. It is commonly found within the margins of rhyolitic lava flows known as obsidian flows. These flows have a high content of silica, granting them a high viscosity.
A macuahuitl ([maːˈkʷawit͡ɬ]) is a weapon, a wooden club with several embedded obsidian blades. The name is derived from the Nahuatl language and means "hand-wood". [2] Its sides are embedded with prismatic blades traditionally made from obsidian, which is capable of producing an edge sharper than high quality steel razor blades.
Obsidian projectile point.. Obsidian is a naturally formed volcanic glass that was an important part of the material culture of Pre-Columbian Mesoamerica.Obsidian was a highly integrated part of daily and ritual life, and its widespread and varied use may be a significant contributor to Mesoamerica's lack of metallurgy.
Diver cutting through a steel beam during welding operations. The most commonly used of the available technologies are oxygen-arc cutting and shielded metal arc cutting. For arc cutting and welding, the workpiece must be cleaned and grounded before an arc can be struck, and the quality of the cut will depend on the surface condition of the ...
The quest for a real life tractor beam continues, with a 2-micrometer-thick silicon light bender. The silicon metasurface changes a solid beam into a triple spiral one that can pick up particles.
Glass knife. A glass knife is a knife with a blade made of glass, with a fracture line forming an extremely sharp cutting edge. Glass knives were used in antiquity due to their natural sharpness and the ease with which they could be manufactured. In modern electron microscopy glass knives are used to make the ultrathin sections needed for imaging.
T-beam. A T-beam (or tee beam), used in construction, is a load-bearing structure of reinforced concrete, wood or metal, with a capital 'T'-shaped cross section. The top of the T-shaped cross section serves as a flange or compression member in resisting compressive stresses. The web (vertical section) of the beam below the compression flange ...
The dimension of a wide-flange I-beam. In the United States, steel I-beams are commonly specified using the depth and weight of the beam. For example, a "W10x22" beam is approximately 10 in (254 mm) in depth with a nominal height of the I-beam from the outer face of one flange to the outer face of the other flange, and weighs 22 lb/ft (33 kg/m).