[meteorite-list] Simple tektite test
From: Matson, Robert <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Thu Apr 22 09:53:36 2004 Message-ID: <AF564D2B9D91D411B9FE00508BF1C86901B4E5BF_at_US-Torrance.mail.saic.com> This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C2A87A.4EEAC380 Content-Type: text/plain; charset="iso-8859-1" Hi All, I believe this test was mentioned a while back by Bob Verish or another list member, but can't you just put a tektite candidate in a microwave oven, blast it for 30 seconds, and see if it gets hot? It is my understanding that tektites (due to the low water content) will not; obsidian, apache tears, terrestrial glass all will. --Rob -----Original Message----- From: N Lehrman [mailto:nlehrman_at_nvbell.net] Sent: Wednesday, December 18, 2002 11:25 PM To: mafer_at_domafer.com Cc: meteorite-list_at_meteoritecentral.com Subject: Re: [meteorite-list] Tektite identification criterion Mark and list, Properties like those you've listed do show helpful variations, but the range between individual tektite types tends to overlap with terrestrial materials to the point that none of this allows one to discriminate between tektites and other materials. Despite the thousands of papers debating the myriad mysteries of tektite lore, I don't know of any that directly address the fundamental question "how do you tell if something is or is not a tektite?". I'd love to hear from any of you out there with ideas or suggested references. I'm going to pull a synthesis of this subject together with time, and there is a reasonable stash of widely scattered data that bear on the subject. The really big challenge though is coming up with criteria that can be used outside of a major university laboratory setting. For example, one of the hallmark characteristics of tektite glass is its exceedingly low water content. However, you'd be hard pressed to find any commercial laboratory that could provide an accurate determination of this property at the levels of resolution we require. Ditto a good ion microprobe analysis. This is all great stuff in the academic laboratory settings where most technical publications originate, but what are we supposed to do out here on the front lines? Of course, there are great folks in academia who will collaborate on worthy issues, but such matters cannot extend to passing judgment on suspect materials that arrive in the mail every other week. You meteorite freaks know the routine well---and have developed a pretty good bag of tricks to screen the winners from the losers. With tektites, we've barely emerged from debating the very definition of the word. Cheers, Norm (TektiteSource.com) ------_=_NextPart_001_01C2A87A.4EEAC380 Content-Type: text/html; charset="iso-8859-1" <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <META content="MSHTML 5.00.3315.2870" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT color=#0000ff face=Arial size=2><SPAN class=629105922-20122002>Hi All,</SPAN></FONT></DIV> <DIV><FONT color=#0000ff face=Arial size=2><SPAN class=629105922-20122002></SPAN></FONT> </DIV> <DIV><FONT color=#0000ff face=Arial size=2><SPAN class=629105922-20122002>I believe this test was mentioned a while back by Bob Verish or another list</SPAN></FONT></DIV> <DIV><FONT color=#0000ff face=Arial size=2><SPAN class=629105922-20122002>member, but can't you just put a tektite candidate in a microwave oven,</SPAN></FONT></DIV> <DIV><FONT color=#0000ff face=Arial size=2><SPAN class=629105922-20122002>blast it for 30 seconds, and see if it gets hot? It is my understanding that</SPAN></FONT></DIV> <DIV><FONT color=#0000ff face=Arial size=2><SPAN class=629105922-20122002>tektites (due to the low water content) will not; obsidian, apache tears,</SPAN></FONT></DIV> <DIV><FONT color=#0000ff face=Arial size=2><SPAN class=629105922-20122002>terrestrial glass all will. --Rob</SPAN></FONT></DIV> <DIV align=left class=OutlookMessageHeader dir=ltr><FONT face=Tahoma size=2>-----Original Message-----<BR><B>From:</B> N Lehrman [mailto:nlehrman_at_nvbell.net]<BR><B>Sent:</B> Wednesday, December 18, 2002 11:25 PM<BR><B>To:</B> mafer_at_domafer.com<BR><B>Cc:</B> meteorite-list_at_meteoritecentral.com<BR><B>Subject:</B> Re: [meteorite-list] Tektite identification criterion<BR><BR></FONT></DIV> <DIV><FONT size=2>Mark and list,</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Properties like those you've listed do show helpful variations, but the range between individual tektite types tends to overlap with terrestrial materials to the point that none of this allows one to discriminate between tektites and other materials.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Despite the thousands of papers debating the myriad mysteries of tektite lore, I don't know of any that directly address the fundamental question "how do you tell if something is or is not a tektite?". I'd love to hear from any of you out there with ideas or suggested references.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>I'm going to pull a synthesis of this subject together with time, and there is a reasonable stash of widely scattered data that bear on the subject. The really big challenge though is coming up with criteria that can be used outside of a major university laboratory setting. For example, one of the hallmark characteristics of tektite glass is its exceedingly low water content. However, you'd be hard pressed to find any commercial laboratory that could provide an accurate determination of this property at the levels of resolution we require. Ditto a good ion microprobe analysis. This is all great stuff in the academic laboratory settings where most technical publications originate, but what are we supposed to do out here on the front lines?</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Of course, there are great folks in academia who will collaborate on worthy issues, but such matters cannot extend to passing judgment on suspect materials that arrive in the mail every other week. You meteorite freaks know the routine well---and have developed a pretty good bag of tricks to screen the winners from the losers. With tektites, we've barely emerged from debating the very definition of the word. </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Cheers,</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Norm</FONT></DIV> <DIV><FONT size=2>(TektiteSource.com)</FONT></DIV></BODY></HTML> ------_=_NextPart_001_01C2A87A.4EEAC380-- Received on Fri 20 Dec 2002 05:51:18 PM PST |
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