The floor seemed to have the texture and give of the volcanic rock.

Many buildings in the city are built out of volcanic rock from the local area.

Mountains of volcanic rock range in age from 1.2 billion to 65 million years old.

This very old building was constructed on a hill of volcanic rock.

At first it found only volcanic rocks on the crater floor.

Volcanic rocks at about the same level have been dated to 76.9 1.2 million years ago.

Because of the volcanic rock, the soil is relatively rich in some areas.

The volcanic rock we found while digging in the backyard.

The dark volcanic rocks were piled up to clear the ground and make walls.

The source for the uranium were most likely volcanic rock units in the area.

Many structures were made from local materials such as coral and volcanic rock.

The island is entirely made up of volcanic rock and sands.

These were embedded in a matrix of soft volcanic rock.

He led her toward a familiar cleft in the volcanic rock face.

This is most likely an indication of volcanic rock underneath the surface.

The hospital sits upon a small rocky rise of black volcanic rock.

It provides the highest exposure of volcanic rock on the island.

It looked like volcanic rock, but it was too late to do anything about that.

In the wild, the dust is formed from fine, ground volcanic rocks.

Decomposing volcanic rock is mostly found by the former lake.

The team dated the fossils and nearby volcanic rock at about 120,000 years old.

Volcanic rock which has been estimated to be 40 million years old overlays the site.

Their dark tone is due to the volcanic rock called basalt.

A vase I recall that was crafted from volcanic rock.

"There are things that are never seen in volcanic rock," he said.