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Unlike ivory, which has no marrow or blood vessel system, bone has a spongy central portion of marrow from which extend tiny blood vessels; bone is therefore highly porous. Bone is also made of both mineral and carbon-based materials; the mineral-based are calcium , phosphorus , and fluoride ; the carbon-based is the protein ossein.
Bone, ivory, and antler are rarely attacked by insects, but horn is often seriously damaged by the larvae of carpet beetles and clothes moths. [7] Light, ultraviolet, and infrared. Ivory, bone, and antler should be kept away from bright light such as spotlights or direct sunlight. Bright light can increase the surface temperature of the object.
Ivory's mechanical properties result from the microstructure of the dentine tissue. It is thought that the structural arrangement of mineralized collagen fibers could contribute to the checkerboard-like Schreger pattern observed in polished ivory samples. [1] This is often used as an attribute in ivory identification.
Bone, Antler, Ivory & Horn: The Technology of Skeletal Materials Since the Roman Period. Barnes and Noble, 1985. [Reprinted 2016, Routledge] This is a scholarly monograph on the subject of horn and other skeletal materials, heavily illustrated, and with extensive academic and art-historical references.
Hornbill ivory: of the many species of hornbill, only the helmeted hornbill (Rhinoplax vigil) furnishes an ivory-like substance. This is a dense, carvable substance that makes up the solid casque growing above the upper mandible (from the bird's forehead). It is not ivory, horn, nor bone, yet it has been called ivory for many centuries.
Growth occurs at the tip, and is initially cartilage, which is later replaced by bone tissue. Once the antler has achieved its full size, the velvet is lost and the antler's bone dies. This dead bone structure is the mature antler. In most cases, the bone at the base is destroyed by osteoclasts and the antlers fall off at some point. [6]
Schreger lines in a mammoth ivory. Schreger lines are visual artifacts that are evident in the cross-sections of ivory. [1] They are commonly referred to as cross-hatchings, engine turnings, or stacked chevrons. Schreger lines can be divided into two categories. The easily seen lines which are closest to the cementum are the outer Schreger lines.
The Anglo-Saxon Franks Casket is a whale bone casket imitating earlier ivory ones. [4] Medieval bone caskets were made by the Embriachi workshop of north Italy (c. 1375 –1425) and others, mostly using rows of thin plaques carved in relief. [5] A face carved on a piece of curved bone. The face is framed by hair and part of a winged head-dress ...