Can anyone identify this finish and how it's achieved?

[bspearson]

Blue Saphire

Classic Ben Hogan Blue Sapphire Milled Putter ?(?¿?)? - eBay (item 280370974826 end time Jul-19-09 18:00:00 PDT)

[spankey666]

the description says its oil quenched, so it must have been heated evenly to between 293 and 315 degrees c and then quenched. the exact colour depends on the temperature , 293 gives a full blue, 315 gives a very dark blue. i guess experimentation will give the results you want.

what you need will involve a pot of heated salt petre.
there is a thread running in one of the other sections that covers this technique