Lynden
a "fish hater"
You can have lava rock as well, but basically you should be aiming for rock that has a good growth of encrusting algae ("sea lichen"). Be sure (living in Honolulu this may be a concern) that the area is not polluted, but if the rock does have a good growth that should be indicative of it's quality.
If you can, look for some hermit crabs and brittle stars as well. Hermits and many snails can be found by looking in tide pools which I'm sure you know, and brittle stars are found under rocks, the same ones that would make good live rock.
Remember to only take smaller (up to a few dozen pounds a piece) pieces and try to be as non-destructive as possible. Also you may need some sort of permit.
If you can, look for some hermit crabs and brittle stars as well. Hermits and many snails can be found by looking in tide pools which I'm sure you know, and brittle stars are found under rocks, the same ones that would make good live rock.
Remember to only take smaller (up to a few dozen pounds a piece) pieces and try to be as non-destructive as possible. Also you may need some sort of permit.