David Glover
Bespoke Innovations. 3-D Printing Is Spurring a Manufacturing Revolution. Pliny the Elder, Naturalis Historia, book preface, chapter 1. Onyx. Onyx is a banded variety of chalcedony.
The colors of its bands range from white to almost every color (save some shades, such as purple or blue). Commonly, specimens of onyx contain bands of black and/or white. Etymology[edit] Onyx comes through Latin (of the same spelling), from the Greek ὄνυξ, meaning "claw" or "fingernail". With its fleshtone color, onyx can be said to resemble a fingernail. Varieties[edit] Black onyx with bands of colors Onyx is formed of bands of chalcedony in alternating colors. Sardonyx is a variant in which the colored bands are sard (shades of red) rather than black. Imitations and treatments[edit] Museo del corallo.
Da Wikipedia, l'enciclopedia libera.
Coordinate: "L'Amore immortale"Cammeo inciso su conchiglia sardonica nei laboratori Ascione, 1925, Napoli, Museo del Corallo Lo spazio museale[modifica | modifica sorgente] È articolato in due sezioni: nella prima, di tipo didattico, sono presentati rami di corallo di diversa provenienza e tipologia, gli antichi sistemi di pesca, gli antichi utensili per la lavorazione, numerose collane nei vari tagli e stili, i mercati ai quali erano e sono destinate. Uno spazio è dedicato anche alla lavorazione del cammeo: le conchiglie, gli strumenti, le fasi di lavorazione, gli oggetti finiti danno al visitatore un quadro completo ed esaustivo di questa particolarissima arte.
La seconda sezione è dedicata alla gioielleria: sono in mostra più di 300 oggetti in corallo, cammei, pietra lavica, testimonianze di una rara e raffinata produzione che va dagli inizi del XIX secolo agli anni quaranta del secolo scorso. La sede[modifica | modifica sorgente] Cameo (carving) Eagle Cameo, Roman 27 B.C.
Two-layered onyx Today the term may be used very loosely for objects with no colour contrast, and other, metaphorical, terms have developed, such as cameo appearance. This derives from another generalized meaning that has developed, the cameo as an image of a head in an oval frame in any medium, such as a photograph. Ancient and Renaissance cameos were made from semi-precious gemstones, especially the various types of onyx and agate, and any other stones with a flat plane where two contrasting colours meet; these are "hardstone" cameos. In cheaper modern work, shell and glass are more common. Gemma Augustea. Gemma Augustea The Gemma Augustea (Latin, Gem of Augustus) is a low-relief cameo engraved gem cut from a double-layered Arabian onyx stone.
It is commonly agreed that the gem cutter who created the Gemma Augustea was either Dioscurides or one of his disciples, in the second or third decade of the 1st century AD. Creation and characteristics[edit] It is commonly agreed that the gem cutter who created Gemma Augustea was either Dioscurides or one of his disciples. Dioscurides was Caesar Augustus’ favorite gem cutter, and his work and copies of it are seen from all over the ancient Roman world. The whereabouts of the gemma is undocumented, though it still remained relatively intact and was probably always above ground, until 1246 when it is recorded in the treasury of the Basilica of St.
Interpretations of the figures and scenes[edit] Gemma Augustea, with reference numbers. Upper tier[edit] Lower tier[edit] The lower register In the lower scene, the figures are less readily identifiable. Alabaster. Three Maries, alabaster sculpture by Master of the Rimini Crucifixion (c. 1430), National Museum, Warsaw.
An uplighter lamp made from Italian alabaster of white and brown types; the base is 5 inches (13 cm) in diameter. Alabaster is a name applied to varieties of two distinct minerals, when used as a material: gypsum (a hydrous sulfate of calcium) and calcite, a carbonate of calcium, also known as onyx-marble, Egyptian alabaster or Oriental alabaster, in geological terms is "a stalagmitic limestone marked with patterns of swirling bands of cream and brown".[1] In general, but not always, ancient Alabaster in Egypt and the Near & Middle East is calcite.
Alabaster in medieval Europe is gypsum. Modern Alabaster is probably calcite, but may be either. Both are easy to 'work' and as both are slightly water soluble, have been used for making a variety of indoor artworks and carvings, as they will not survive long outdoors. 3d printing. Charrette. A charrette (pronounced [shuh-ret]), often Anglicized to charette or charet and sometimes called a design charrette, is an intense period of design or planning activity.
Charrettes in general[edit] The word charrette may refer to any collaborative session in which a group of designers drafts a solution to a design problem. While the structure of a charrette varies, depending on the design problem and the individuals in the group, charrettes often take place in multiple sessions in which the group divides into sub-groups. Each sub-group then presents its work to the full group as material for further dialogue. Guns, Germs, and Steel: The Fates of Human Societies (9780393317558): Jared M. Diamond. Disappearing Spoon « Periodic table stories by Sam Kean. The Periodic Table: One of man’s crowning scientific achievements … and a treasure trove of passion, adventure, betrayal, and obsession Why did Gandhi hate iodine (I, 53)?
Why did the Japanese kill Godzilla with missiles made of cadmium (Cd, 48)? How did radium (Ra, 88) nearly ruin Marie Curie’s reputation? And why did tellurium (Te, 52) lead to the most bizarre gold rush in history? The Periodic Table is one of our crowning scientific achievements, but it’s also a treasure trove of passion, adventure, betrayal, and obsession.
Why did a little lithium (Li, 3) help cure poet Robert Lowell of his madness? *Though solid at room temperature, gallium is a moldable metal with a unique property—it melts at 84° F. Read an excerpt. The Evolution of Useful Things: How Everyday Artifacts-From Forks and Pins to Paper Clips and Zippers-Came to be as They are (9780679740391): Henry Petroski.