How about "Silver" by Naveed Akram :
Silver is a wonderful element,
A fierce wonder, much honoured;
And its help is great, forever,
And forever. I give in to silver.
For silver I take the number of days
To be many for the occupation of mine.
The silvered men and women
Are never the forgotten people;
So choose silver, and wise are you.
Silver is the best metal
Too hard to possess.
There are not a lot of poems that are about a specific element. You might try a look through this link at poemhunter , which is where I found the one above. There are also some neat ones at the Poetic Table of the Elements - just click on "silver" and a list of them will pop up.