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Hardstone
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. 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. Hardstone carving is the three-dimensional carving for artistic purposes of semi-precious stones such as jade, agate, onyx, rock crystal, sard or carnelian, and a general term for an object made in this way. Two-dimensional inlay techniques for floors, furniture and walls include pietre dure, opus sectile (Ancient Roman), and medieval Cosmatesque work these typically inlay hardstone pieces into a background of marble or some other building stone. The definition of "hardstone" is not very rigid, but excludes "soft" stones such as soapstone (steatite) and minerals such as alabaster, both widely used for carving. Hard organic mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardstone Carving
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. Normally the objects are small, and the category overlaps with both jewellery and sculpture. Hardstone carving is sometimes referred to by the Italian term ''pietre dure''; however, ''pietra dura'' (with an "a") is the common term used for stone inlay work, which causes some confusion. From the Neolithic period until about the 19th century such objects were among the most highly prized in a wide variety of cultures, often attributed special powers or religious significance, but today coverage in non-specialist art history tends to be relegated to a catch-all decorative arts or "minor arts" category. The types of objects carved have included those with ritual or religious purposes, engraved gems as signet rings and other kinds of seal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pietre Dure
''Pietra dura'' (), ''pietre dure'' () or intarsia lapidary ( see below), called ''parchin kari'' or ''parchinkari'' () in the Indian subcontinent, is a term for the inlay technique of using cut and fitted, highly polished colored stones to create images. It is considered a decorative art. The stonework, after the work is assembled loosely, is glued stone-by-stone to a substrate after having previously been "sliced and cut in different shape sections, and then assembled together so precisely that the contact between each section was practically invisible". Stability was achieved by grooving the undersides of the stones so that they interlocked, rather like a jigsaw puzzle, with everything held tautly in place by an encircling 'frame'. Many different colored stones, particularly marbles, were used, along with semiprecious, and even precious stones. It first appeared in Rome in the 16th century, reaching its full maturity in Florence. ''Pietra dura'' items are generally crafted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agate
Agate ( ) is a banded variety of chalcedony. Agate stones are characterized by alternating bands of different colored chalcedony and sometimes include macroscopic quartz. They are common in nature and can be found globally in a large number of different varieties. There are some varieties of chalcedony without bands that are commonly called agate ( moss agate, fire agate, etc.); however, these are more properly classified solely as varieties of chalcedony. Agates are primarily formed as nodules within volcanic rock, but they can also form in veins or in sedimentary rock. Agate has been popular as a gemstone in jewelry for thousands of years, and today it is also popular as a collector's stone. Some duller agates sold commercially are artificially dyed to enhance their color. Etymology Agate was given its name by Theophrastus, a Greek philosopher and naturalist. He discovered the stone c. 350 BCE along the shoreline of the River Achates (), now the Dirillo River, on the Italian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opus Sectile
''Opus sectile'' is a form of '' pietra dura'' popularized in the ancient and medieval Roman world where materials were cut and inlaid into walls and floors to make a picture or pattern. Common materials were marble, mother of pearl, and glass. The materials were cut in thin pieces, polished, then trimmed further according to a chosen pattern. Unlike tessellated mosaic techniques, where the placement of very small uniformly sized pieces forms a picture, ''opus sectile'' pieces are much larger and can be shaped to define large parts of the design. The term ''opus sectile'' was introduced in recent centuries, but the Romans used the term ''sectilia pavimenta''. Origin and evolution Early examples It appeared in Rome in the first decades of the 1st c. BC when "stone slab floors came into use, at least in the smaller element type". Under Augustus, its use in the flooring of public buildings began. The success of the first experiments on a monumental scale led to its applicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jade
Jade is an umbrella term for two different types of decorative rocks used for jewelry or Ornament (art), ornaments. Jade is often referred to by either of two different silicate mineral names: nephrite (a silicate of calcium and magnesium in the amphibole group of minerals), or jadeite (a silicate of sodium and aluminum in the pyroxene group of minerals). Nephrite is typically green, although may be yellow, white or black. Jadeite varies from white or near-colorless, through various shades of green (including an emerald green, termed 'imperial'), to Lavender (color), lavender, yellow, orange, brown and black. Rarely it may be blue. Both of these names refer to their use as gemstones, and each has a mineralogically more specific name. Both the amphibole jade (nephrite) and pyroxene jade are mineral aggregates (rocks) rather than mineral species. Nephrite was deprecated by the International Mineralogical Association as a mineral species name in 1978 (replaced by tremolite). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soapstone
Soapstone (also known as steatite or soaprock) is a talc-schist, which is a type of metamorphic rock. It is composed largely of the magnesium-rich mineral talc. It is produced by dynamothermal metamorphism and metasomatism, which occur in subduction zones, changing rocks by heat and pressure, with influx of fluids but without melting. It has been a carving medium for thousands of years. Terminology The definitions of the terms "steatite" and "soapstone" vary with the field of study. In geology, steatite is a rock that is, to a very large extent, composed of talc. The mining industry defines steatite as a high-purity talc rock that is suitable for the manufacturing of, for example, insulators; the lesser grades of the mineral can be called simply "talc rock". Steatite can be used both in lumps ("block steatite", "lava steatite", "lava grade talc"), and in the ground form. While the geologists logically will use "steatite" to designate both forms, in the industry, "steatite" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minerals
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Minerals'; p. 1. In the series ''Geology: Landforms, Minerals, and Rocks''. Rosen Publishing Group. The geological definition of mineral normally excludes compounds that occur only in living organisms. However, some minerals are often biogenic (such as calcite) or organic compounds in the sense of chemistry (such as mellite). Moreover, living organisms often synthesize inorganic minerals (such as hydroxylapatite) that also occur in rocks. The concept of mineral is distinct from rock, which is any bulk solid geologic material that is relatively homogeneous at a large enough scale. A rock may consist of one type of mineral or may be an aggregate of two or more different types of minerals, spacially segregated into distinct phases. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alabaster
Alabaster is a mineral and a soft Rock (geology), rock used for carvings and as a source of plaster powder. Archaeologists, geologists, and the stone industry have different definitions for the word ''alabaster''. In archaeology, the term ''alabaster'' includes objects and artefacts made from two different minerals: (i) the fine-grained, massive type of gypsum, and (ii) the fine-grained, banded type of calcite.''More About Alabaster and Travertine'': Brief Guide explains the different definitions used by geologists, archaeologists, and the stone trade. Oxford University Museum of Natural History, 2012/ref> Chemically, gypsum is a Water of crystallization, hydrous sulfate of calcium, whereas calcite is a carbonate of calcium. As types of alabaster, gypsum and calcite have similar properties, such as light color, translucence, and soft stones that can be sculpture, carved and sculpted; thus the historical use and application of alabaster for the production of carved, decorative art ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amber
Amber is fossilized tree resin. Examples of it have been appreciated for its color and natural beauty since the Neolithic times, and worked as a gemstone since antiquity."Amber" (2004). In Maxine N. Lurie and Marc Mappen (eds.) ''Encyclopedia of New Jersey'', Rutgers University Press, . Amber is used in jewelry and as a healing agent in Traditional medicine, folk medicine. There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material as Inclusion (mineral), inclusions. Amber occurring in coal seams is also called resinite, and the term ''ambrite'' is applied to that found specifically within New Zealand coal seams. Etymology The English word ''amber'' derives from Arabic from Middle Persian š šš”š« (''Ź¾nbl'' /ā ambarā /, āambergrisā) via Medieval Latin, Middle Latin ''ambar'' and Middle French ''ambre''. The word referred to what is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jet (lignite)
Jet, Jets, or The Jet(s) may refer to: Aerospace * Jet aircraft, an aircraft propelled by jet engines ** Jet airliner ** Jet engine ** Jet fuel * Jet Airways, an Indian airline * Super Air Jet, an Indonesian airline * Wind Jet (ICAO: JET), an Italian airline * Journey to Enceladus and Titan (JET), a proposed astrobiology orbiter to Saturn * Jet pack, a backpack personal flying device containing a jet motor * Fighter jet, a military aircraft Aircraft * Business jet ** Boeing Business Jet * Very light jet ** Cirrus Vision SF50, originally called "The-Jet by Cirrus" ** Eclipse 400, originally called "Eclipse Concept Jet" ** Honda HA-420 HondaJet ** Piper PA-47 PiperJet Other areas of science, math, and technology * Jet (fluid), a coherent stream of fluid that is projected into a surrounding medium, usually from some kind of a nozzle or aperture * Jet (gemstone), a black or brown semi-precious mineraloid * Jet (mathematics), an operation on a differentiable function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineraloid
A mineraloid is a naturally occurring substance that resembles a mineral, but does not demonstrate the crystallinity of a mineral. Mineraloid substances possess chemical compositions that vary beyond the generally accepted ranges for specific minerals, for example, obsidian is an amorphous glass and not a true crystal; lignite ( jet) is derived from the decay of wood under extreme pressure underground; and opal is a mineraloid substance because of its non-crystalline nature. Pearl is a mineraloid substance because the calcite crystals and the aragonite crystals are bonded by an organic material, and naturally occurs without definite proportions of the components. The first usage of the term ''mineraloid'' substance was in 1909, by mineralogist and geologist Julian Niedzwiedzki, in identifying and describing amorphous substances that resemble minerals. Examples * Allophane, solid (IMA/CNMNC valid mineral name) * Amber, non-crystalline structure, organic * Anthracite or ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obsidian
Obsidian ( ) is a naturally occurring volcanic glass formed when lava extrusive rock, extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Produced from felsic lava, obsidian is rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. It is commonly found within the margins of rhyolite, rhyolitic lava flows known as obsidian flows. These flows have a high content of silicon dioxide, silica, giving them a high viscosity. The high viscosity inhibits the atomic diffusion, diffusion of atoms through the lava, which inhibits the first step (nucleation) in the formation of mineral crystals. Together with rapid cooling, this results in a natural glass forming from the lava. Obsidian is hard, Brittleness, brittle, and amorphous; it therefore Fracture (mineralogy)#Conchoidal fracture, fractures with sharp edges. In the past, it was used to manufacture cutting and piercing tools, and it has been used experimentally as s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
