Wielding Absurdly Large and Heavy Improvised Weapons

[Talverin]

Don't ask me how I got here, or the sacrifices I had to make with the character, but I am trying to parse out what kind of objects I can throw, and what kind of damage they can do.

Currently, I can throw improvised weapons that are up to Colossal size, and weigh up to 3728 pounds.

For reference, one cubic foot of granite weighs ~175 pounds, so I can throw ~21 cubic feet of boulder. Oak is ~45 pounds per cubic foot, allowing me to throw a length of tree that's two feet around and twenty feet long.

What other, similar objects could I throw, and what, in your mind, would be the appropriate damage (Or additional effects) for objects like them?

[Eldonauran]

Density doesn't really factor into the damage in Pathfinder, except in specific (unique) circumstances. You would probably be best suited to using the falling damage table in Environmental Rules in the Core Rulebook.

Damage for Colossal is 10d6. I'd let you add your strength modifier (or 1.5x Str) to the damage. Try a Vital Strike throw for more damage.

[Talverin]

When you say 'Damage for colossal' what are you citing?

[Florian]

You might want to look at giants and their rock throwing ability. Now despair that mass and physics don´t play a role in PF. (Or be glad, else every encounter with something large and upwards would be a pure save or die)

[Eldonauran]

When you say 'Damage for colossal' what are you citing?

Falling object damage under the Enivornmental Rules (http://www.d20pfsrd.com/gamemastering/environment/environmental-rules/). If something Colossal falls on you, it typically does 10d6 damage. Since you aren't referencing an actual weapon...