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colored metals
https://www.gemologyonline.com/Forum/phpBB2/viewtopic.php?f=19&t=6133
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Author:  Brian [ Mon Jun 30, 2008 2:01 am ]
Post subject:  colored metals

Seeing the various threads about "white" gold made me recall an interesting fact that I thought I'd turn into a quiz question.

The periodic table of elements can be separated into metals and non-metals. Among the metals, only three reflect colored light. All the other metals appear silver or gray. Two of these color-reflecting metals are gold and copper. What is the third? :)

And if you are thinking "brass"... :( sorry, that isn't an element, it is an alloy of zinc and copper whose color reflection comes from the copper.

Sorry, no prize for correct answer. :cry:

Author:  allen [ Mon Jun 30, 2008 3:53 am ]
Post subject: 

OK, I'll bite. It either has to be silver (white) or bismuth (pink) depending on your definition of "color".
Clearly I had to search the periodic table to come up with bismuth. Not even sure what it is used for but certainly not jewelry.

Author:  Jason [ Mon Jun 30, 2008 6:31 am ]
Post subject: 

I"m going with Bismuth too.

J-

I WANT A PRIZE! :D How bout a free spectrometer? hehe

Author:  Brian [ Mon Jun 30, 2008 8:44 am ]
Post subject: 

Nope.

I have some bismuth shot (a nice replacement for lead shot if you are an eco-friendly fisherman), and it is pretty much gray. And silver is pretty much silver.

This metal element has an unmistakable color.

Author:  Alberto [ Mon Jun 30, 2008 9:08 am ]
Post subject: 

Cesium?

Author:  Scaramouche [ Mon Jun 30, 2008 9:58 am ]
Post subject: 

After a bout of periodic table reading, I'll bet on osmium, described as blue/grey or blue/black.

Doesn't sound promissing, I know.

Author:  Alberto [ Mon Jun 30, 2008 10:04 am ]
Post subject: 

Tantalium is described like bluish-gray.....

Author:  Brian [ Mon Jun 30, 2008 10:43 am ]
Post subject: 

Alberto wins with his first answer. Cesium. :smt038

Author:  Alberto [ Mon Jun 30, 2008 11:02 am ]
Post subject: 

ok Prof,
i hope i won more answers on spectrometer setup 8)
ciao
alberto

Author:  allen [ Mon Jun 30, 2008 2:21 pm ]
Post subject: 

Descriptions from the periodic table (Wickepedia):

Bismuth- lustrous pink
Cesium- silvery gold
Silver- lustrous white

Maybe your Bismuth fishing weights are not pure Bismuth?

Author:  maialetto [ Mon Jun 30, 2008 4:20 pm ]
Post subject: 

In some metals the "color" is due to a film of the metal oxide in the surface. I think the most "famous" is titanium: you can get a variety of colors varying e.g. the oxide film thickness, but the metal itself is gray.
With Bi the situation should be very smilar.

Author:  Brian [ Mon Jun 30, 2008 10:16 pm ]
Post subject: 

Just because you find a piece of iron with orange coloring on its surface doesn't mean that iron is orange. Similarly, bismuth may in some cases have a pink coloring on its surface, but the metal itself is pretty much gray.

Author:  maialetto [ Tue Jul 01, 2008 4:08 pm ]
Post subject: 

Brian wrote:
Just because you find a piece of iron with orange coloring on its surface doesn't mean that iron is orange.


That's why I put "color" between quotes :)

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