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From: larry@kitty.UUCP
Newsgroups: sci.misc
Subject: Re: Osmium?
Message-ID: <1804@kitty.UUCP>
Date: Wed, 17-Jun-87 00:50:28 EDT
Article-I.D.: kitty.1804
Posted: Wed Jun 17 00:50:28 1987
Date-Received: Fri, 19-Jun-87 00:49:53 EDT
References: <1754@ames.UUCP> <336@gtx.com>
Distribution: na
Organization: Recognition Research Corp., Clarence, NY
Lines: 42
Keywords: osmium
Summary: A dense story...

In article <336@gtx.com>, al@gtx.com (0732) writes:
> ->    I have a strange request ... does anyone in netland know where I can
> ->get some of osmium?  

	You can try the Alfa Products division of Morton Thiokol, located
in Danvers, MA., but I doubt that they will sell directly to individuals.
	One gram of pure osmium in 60 mesh powder form costs approximately
$ 93.00.  The catalog number is 00246.
	Pure osmium is a skin irritant at room temperature, but is
significantly toxic when heated in air at a temperature greater than
130 deg C.  When so heated, osmium combines with oxygen in the atmosphere
to form osmium tetroxide (a/k/a osmic acid).  It is osmium tetroxide
which has a pungent, disagreeable odor.

> ->    I have heard it is the most dense substance on earth, denser than 
> ->gold or lead. I think it would be fun to have a baseball size hunk of it 
> ->on my desk as a paper weight.

	Osmium is the densest metal, having a specific gravity of 20.1.
I believe that a "baseball size" hunk of osmium would cost quite a few
kilobucks, considering the above price per gram.

> I remember a few years ago (like maybe 20) that some brand of ball point
> pen was advertised to have an osmium tip.  You could get a few hundred 
> thousand old pens, castrate them, test them to see which balls are 
> osmium (smell them?) and melt them down. But seriously, what property
> of osmium would make it a choice for a ball-point pen tip?

	Osmium and its alloys are unusually resistant to wear and corrosion,
and therefore make an ideal (but expensive) material for pen points.  The
effective resistance of osmium to rubbing wear is very high, and is far
greater than one would predict from mere density.
	Osmium is used in pen points and nibs, meter pivots, electrical
contacts, and phonograph styli.
	Osmium melts at about 2700 deg C.  The metal is totally unworkable
by conventional machining methods, and can only be shaped by grinding,
melting and powder metallurgy.

<>  Larry Lippman @ Recognition Research Corp., Clarence, New York
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