[tgb]

You can but only under very arbitrary situations that aren't common in real life. And if you're assuming it's not hollow and has constant density, then I doubt there's any way to make such an iceberg except if you look at it from one specific angle: looking from the side should give it away. Yet nearly every image of an iceberg seems to show them in that way.

[Retric]

That’s a different question. In practice floating icebergs are often at a local minima not the global minima. They can be at very unstable orientations in calm seas. The constant melting process promotes instability.