Diamond Discs - What's the Difference?

[Turbo]

I got this set of discs to make a tungsten sharpener.
http://www.ebay.co.uk/itm/262491048...49&var=561306399609&ssPageName=STRK:MEBIDX:IT
http://www.ebay.co.uk/itm/262491048...49&var=561306399609&ssPageName=STRK:MEBIDX:IT
There's 2 silver discs, one segmented and a gold one. Can anyone tell me the difference in the 3 as regards suitability for grinding electrodes?

 

[Brad93]

Use the plain silver one, the segmented one probably wouldn't do any harm though.