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Granulation (jewellery)
Granulation is a jewellery manufacturing technique whereby a surface is covered in spherules or granules of precious metal. The technique is thought to have its origins in Sumer about 5,000 years ago. This technique then spread to southern Europe during the orientalizing period, also through the role of Phoenicians, who had founded colonies in Sardinia, Sicily and Spain, or Near Eastern craftsmen. In the first millennium B.C. the technique was used by Etruscans living in present-day Italy. Greek craftsmen also employed the technique, but it was the work coming from Etruria which became famous, in part due to the mysteries surrounding the process. Methods This technique is notoriously difficult and mysterious in the jewelry world. So much that Ancient Greeks had young children place granules due to the extreme patience and near perfect eyesight needed to place each granule onto the base of the metal being fused. Granulation may be employed in three elaborate ways: the outline st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earring Etruscan BM 2256
An earring is a piece of jewelry attached to the ear via a Body piercing, piercing in the earlobe or another external part of the ear (except in the case of clip earrings, which clip onto the lobe). Earrings have been worn by people in different civilizations and historic periods, often with cultural significance. Locations for piercings other than the earlobe include the Rook (piercing), rook, Tragus piercing, tragus, and across the Helix (ear), helix (see image at right). The simple term "ear piercing" usually refers to an earlobe piercing, whereas piercings in the upper part of the Pinna (anatomy), external ear are often referred to as "cartilage piercings". Cartilage piercings are more complex to perform than earlobe piercings and take longer to heal. Earring components may be made of any number of materials, including metal, plastic, glass, gemstone, precious stone, beads, wood, bone, and other materials. Designs range from small hoops and studs to large plates and dangling i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tragacanth
Tragacanth is a natural gum obtained from the dried sap of several species of Middle Eastern legumes of the genus ''Astragalus'', including '' A. adscendens'', '' A. gummifer'', '' A. brachycalyx'', and '' A. tragacantha''. Some of these species are known collectively under the common names "goat's thorn" and "locoweed". The gum is sometimes called Shiraz gum, shiraz, gum elect or gum dragon. The name derives from the Greek words ''tragos'' (meaning "goat") and ''akantha'' ("thorn"). Iran is the biggest producer of this gum. Gum tragacanth is a viscous, odorless, tasteless, water-soluble mixture of polysaccharides obtained from sap that is drained from the root of the plant and dried. The gum seeps from the plant in twisted ribbons or flakes that can be powdered. It absorbs water to become a gel, which can be stirred into a paste. The major fractions are known as tragacanthin, highly water-soluble as a mucilaginous colloid, and the chemically related bassorin, which is far less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jewellery
Jewellery ( UK) or jewelry (U.S.) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a western perspective, the term is restricted to durable ornaments, excluding flowers for example. For many centuries metal such as gold often combined with gemstones, has been the normal material for jewellery, but other materials such as glass, shells and other plant materials may be used. Jewellery is one of the oldest types of archaeological artefact – with 100,000-year-old beads made from ''Nassarius'' shells thought to be the oldest known jewellery.Study reveals 'oldest jewellery' , '' |
Yemenite Silversmithing
Yemenite silversmithing refers to the work of Jewish silversmiths from Yemen. They were highly acclaimed craftsmen who dominated craft production in precious metals in the southern Arabian peninsula from at least the 18th through the mid-20th century, a period and region during which Muslims did not engage in this work. These Yemenite silversmiths were noted for their skilled use of fine granulation and filigree, producing ornaments such as women's bracelets, necklaces, finials, as well as elaborate scabbard sheaths for men's daggers (). History Yemenite silversmiths, a trade held almost exclusively by Jews living in the traditional Yemeni society, were active from at least as far back as the mid-1700s. The largest clientele for jewellery made of gold and silver were women, and the amount of jewellery worn was often an indicator of the woman's status.Guilat, Yael (2018), p. 227 Some Yemenite silversmiths migrated to Palestine in the late 1800s, a migration that continued i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jewellery Of The Berber Cultures
Jewellery of the Berber cultures (Tamazight language'': iqchochne imazighne,'' ⵉⵇⵇⵛⵓⵛⵏ ⵉⵎⴰⵣⵉⵖⵏ) is a historical style of traditional jewellery that was worn by women mainly in rural areas of the Maghreb region in North Africa and inhabited by indigenous Berber people (in the Berber language Tamazight: ''Amazigh'' (sg.)'', Imazighen'', pl). Following long social and cultural traditions, Berber or other silversmiths in Morocco, Algeria and neighbouring countries created intricate jewellery with distinct regional variations. In many towns and cities, there were Jewish silversmiths, who produced both jewellery in specific Berber styles as well as in other styles, adapting to changing techniques and artistic innovations. Handing their jewellery on from generation to generation, as a visual element of the Berber ethnic identity, women maintained this characteristic cultural tradition as part of their gender-specific adornments. As Berber communities have b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliny The Elder
Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic ''Naturalis Historia'' (''Natural History''), which became an editorial model for encyclopedias. He spent most of his spare time studying, writing, and investigating natural and geographic phenomena in the field. His nephew, Pliny the Younger, wrote of him in a letter to the historian Tacitus: Among Pliny's greatest works was the twenty-volume work ''Bella Germaniae'' ("The History of the German Wars"), which is no longer extant. ''Bella Germaniae'', which began where Aufidius Bassus' ''Libri Belli Germanici'' ("The War with the Germans") left off, was used as a source by other prominent Roman historians, including Plutarch, Tacitus and Suetonius. Tacitus—who many scholars agree had never travelled in Germania—used ''Bella Germani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capillary Action
Capillary action (sometimes called capillarity, capillary motion, capillary rise, capillary effect, or wicking) is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a biological cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid. Etymology Capillary comes from the Latin word capillaris, meaning "of or resembling hair." The meaning stems from the tiny, hairlike diameter of a capillary. While capilla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusion Welding
Fusion welding is a generic term for welding processes that rely on melting to join materials of similar compositions and melting points. Due to the high-temperature phase transitions inherent to these processes, a heat-affected zone is created in the material (although some techniques, like beam welding, often minimize this effect by introducing comparatively little heat into the workpiece). In contrast to fusion welding, solid-state welding does not involve the melting of materials. Applications Fusion welding has been a critical factor in the creation of modern civilization due to its vital role in construction practices. Besides bolts and rivets, there are no other practical methods for joining pieces of metal securely. Fusion welding is used in the manufacture of many everyday items, including airplanes, cars, and structures. A large community uses both arc and flame contact welding to create artwork. Types Electrical Arc Arc welding is one of the many types of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reducing Atmosphere
A reducing atmosphere is an atmospheric condition in which oxidation is prevented by removal of oxygen and other oxidizing gases or vapours, and which may contain actively reducing gases such as hydrogen, carbon monoxide, and gases such as hydrogen sulfide that would be oxidized by any present oxygen. Although early in its history the Earth had a reducing atmosphere, it now instead has an oxidizing atmosphere with molecular oxygen (dioxygen, O2) as the primary oxidizing agent. Foundry operations The principal mission of iron foundry is the conversion of iron oxides (purified iron ores) to iron metal. This reduction is usually effected using a reducing atmosphere consisting of some mixture of natural gas, hydrogen (H2), and carbon monoxide. The byproduct is carbon dioxide. Metal processing In metal processing, a reducing atmosphere is used in annealing ovens for relaxation of metal stresses without corroding the metal. A non-oxidizing gas, usually nitrogen or argon, is typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sumer
Sumer () is the earliest known civilization in the historical region of southern Mesopotamia (south-central Iraq), emerging during the Chalcolithic and early Bronze Ages between the sixth and fifth millennium BC. It is one of the cradles of civilization in the world, along with ancient Egypt, Elam, the Caral-Supe civilization, Mesoamerica, the Indus Valley civilisation, and ancient China. Living along the valleys of the Tigris and Euphrates rivers, Sumerian farmers grew an abundance of grain and other crops, the surplus from which enabled them to form urban settlements. Proto-writing dates back before 3000 BC. The earliest texts come from the cities of Uruk and Jemdet Nasr, and date to between c. 3500 and c. 3000 BC. Name The term "Sumer" ( Sumerian: or , Akkadian: ) is the name given to the language spoken by the "Sumerians", the ancient non- Semitic-speaking inhabitants of southern Mesopotamia, by their successors the East Semitic-speaking Akkadians. The Sumerians ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carat (purity)
The fineness of a precious metal object (coin, bar, jewelry, etc.) represents the weight of ''fine metal'' therein, in proportion to the total weight which includes alloying base metals and any impurities. Alloy metals are added to increase hardness and durability of coins and jewelry, alter colors, decrease the cost per weight, or avoid the cost of high-purity refinement. For example, copper is added to the precious metal silver to make a more durable alloy for use in coins, housewares and jewelry. Coin silver, which was used for making silver coins in the past, contains 90% silver and 10% copper, by mass. Sterling silver contains 92.5% silver and 7.5% of other metals, usually copper, by mass. Various ways of expressing fineness have been used and two remain in common use: ''millesimal fineness'' expressed in units of parts per 1,000 and '' karats'' or ''carats'' used only for gold. Karats measure the parts per 24, so that 18 karat = = 75% and 24 karat gold is considered 100% g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
