High-purity titanium crystal bar with an embedded molybdenum electrode. This is the cut-off end of a long crystal bar, the remainder having been turned into titanium metal stock: These crystal bars are the final stage of purification before the metal is fabricated into desired shapes, or used to make alloys. My guess is that they don't use the titanium at the end right near the electrode because a certain amount of molybdenum contamination diffuses into the metal as it is being deposited, but that's pure speculation on my part.
It's hard to show in pictures but the surface of this bar consists of beautifully shiny, mirror-like concave and convex surfaces quite reminiscent of hafnium crystal bar formed by iodic decomposition: The 3D rotatable image shows this much better than the normal photo.
Source: Wah Chang
Contributor: Wah Chang
Acquired: 14 May, 2004