Search results
Results from the WOW.Com Content Network
Mughal dagger hilt in jade with gold, rubies, and emeralds.. Hardstone carving, in art history and archaeology, is the artistic carving of semi-precious stones (and sometimes gemstones), such as jade, rock crystal (clear quartz), agate, onyx, jasper, serpentinite, or carnelian, and for objects made in this way.
Flaked stone reduction involves the use of a hard hammer percussor, such as a hammerstone, a soft hammer fabricator (made of wood, bone or antler), or a wood or antler punch to detach lithic flakes from the lithic core. As flakes are detached in sequence, the original mass of stone is reduced; hence the term for this process.
Hardstone is a non-scientific term, mostly encountered in the decorative arts or archaeology, that has a similar meaning to semi-precious stones, or gemstones. [1] Very hard building stones, such as granite, are not included in the term in this sense, but only stones which are fairly hard and regarded as attractive – ones which could be used in jewellery.
Stone pitching tools are used to remove large quantities of stone. Stone nickers are used to split stones by tracing a line along the stone with progressive strikes until the stone breaks along the line. Powered pneumatic hammers make the hard work easier. Progress on shaping stone is faster with pneumatic carving tools.
Granite is a hard stone and requires skill to carve by hand. Until the early 18th century, in the Western world, granite could be carved only by hand tools with generally poor results. A key breakthrough was the invention of steam-powered cutting and dressing tools by Alexander MacDonald of Aberdeen , inspired by seeing ancient Egyptian granite ...
Skarn – Hard, coarse-grained, hydrothermally altered metamorphic rocks Slate – Metamorphic rock - A low grade metamorphic rock formed from shale or silt Suevite – Rock consisting partly of melted material formed during an impact event – A rock formed by partial melting during a meteorite impact
There are two principal phases of underground mining: development mining and production mining. Development mining is composed of excavation almost entirely in (non-valuable) waste rock in order to gain access to the orebody. There are six steps in development mining: remove previously blasted material (muck out round), scaling (removing any unstable slabs of rock hanging from the roof and ...
c) Wedging –This method is used when the hard rock consists of natural fissure. When natural fissures are absent then artificial fissures are prepared by drilling holes. d) Blasting – It is the process of removal of stones with the help of controlled explosives is filled in the holes of the stones. Line of least resistance plays very ...