af his067 » tirs 17. apr 2012 14:10
Hej Classic,
Obsidian er en vulkansk glasart som kan forarbejdes ligesom fedtsten. Da Spanierne kom til sydamerika kendte hverken Inkaer elle Maya til metal våben men brugte istedet Obsidian til at lave knive og andre "skæreapperater". Obsidian splintrer let og var derfor ikke megen hjælp imod Spaniernes metalsvær og rustninger.
Her er et udklip fra Wikipedia:
Obsidian has been used for blades in surgery, as well-crafted obsidian blades have a cutting edge many times sharper than high-quality steel surgical scalpels, the cutting edge of the blade being only about 3 nanometers thick.[15] Even the sharpest metal knife has a jagged, irregular blade when viewed under a strong enough microscope; when examined even under an electron microscope an obsidian blade is still smooth and even. One study found that obsidian incisions produced narrower scars, fewer inflammatory cells, and less granulation tissue in a group of rats.[16] Don Crabtree produced obsidian blades for surgery and other purposes,[15] and has written articles on the subject.
Obsidian is also used for ornamental purposes and as a gemstone. It possesses the property of presenting a different appearance according to the manner in which it is cut: when cut in one direction it is jet black; in another it is glistening gray. "Apache tears" are small rounded obsidian nuggets embedded within a grayish-white perlite matrix.
Plinths for audio turntables have been made of obsidian since the 1970s; e.g. the greyish-black SH-10B3 plinth by Technics.
Oracle Delphi Mk 5.5, Mørch DP-8, PT: Ortofon SPU Royal N, NLE22 med batteriforsyninger, Lyngdorf CD2, Roon Rock, Lyngdorf TDAI 3400, Sansui PS 112C HT kabler, Martin Logan Vantage....og en frygtelig masse andet.