Re: [ATM] Cerium Oxide.. and Color

[Guy Brandenburg <gfbrandenburg@yahoo.com>]

Here is what Newport claim the composition of cerium
oxide is:
CHEMICAL NAME	%
Rare Earth Oxide	30-65%
Calcium Oxide	10-15%
Strontium Oxide	1-6%
Alumina Silicate	1-40%
Fluorides	4-10%
Silica	2%

But they also have a MSDS for 'batnasite', also known
as cerium-r oxide, which is 100% bastnasite. However,
Bastnasite is actually Ce(CO3)F and is weakly
readioactive. See
http://webmineral.com/data/Bastnasite-(Ce).shtml

Also, read this about Cerium Oxide:
http://hps.org/publicinformation/ate/q620.html

and
http://www.reade.com/Products/Oxides/cerium_oxide.html

this is about lapidary, but is interesting as well:
http://www.ganoksin.com/borisat/nenam/buffing-material.htm

Have a good holiday. But no, I'm not into cannibalism!

Guy

--- Daniel Fundo <fundo@bellsouth.net> wrote:
> <<  I just looked at the Materials Data Safety
> Sheets for
> rouge, cerium oxide, pitch, rosin and so on that are
> posted at Newport Glass. I was quite surpised to see
> that cerium oxide has such a high amount of
> impurities
> in it. 
> Worth looking into.  >>
> 
> Guy,  Most folks don't know what an MSDS is!  I'm
> surprised that they
> list the impurities on it, unless, of course, they
> are that significant
> .....are they???  <G>  I'll have to look now.
> 
> My first few mirrors, all 6", were polished and
> figured completely with
> red rouge.  Rouge was safe back then; too many folks
> had really bad
> sleeking (bordering on scratching) problems with
> cerium oxide.  In 1966,
> a friend was making a 10" quartz Cass primary to
> match a secondary from
> a Tinsley telescope he had gotten, and asked me to
> help.  We used CeO on
> it, and it still took something 40 hours to
> polish!!!  We really
> bulls-eyed that one....the primary ended up less
> than 2 mm off the
> Tinsley spec for the f.l.
> 
> I have used CeO ever since for polishing, but always
> figured with red
> rouge.  Scott Rychnovsky (sp)  sent me a "nickle
> bag" of black rouge a
> few years ago and I used it to touch up a problem
> 10" plate glass mirror
> for a member down here.  I didn't improve the figure
> that much, but I
> sure smoothed it out.  I've always used epsilon
> Lyrae as a
> benchmark....the lower the power used to resolve it
> the better.  He
> couldn't resolve it at less the 120x as he bought
> it, but could do it
> easily at about 70x afterward.  (Brag mode on....I
> can resolve it at 62x
> in my 6" f/5.2 that I have been using since
> 1962!!....brag mode off <G>)
> 
> Happy Easter, if you are of the Christian persusion
> *****-----
> Dan F.
> Secretary/MAS
> Memphis, TN
> 

Guy  Brandenburg
Washington, DC
My home page:
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
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