Blue Biggs Jasper stone. Blue Biggs Jasper is a silicated volcanic ash. It was formed during a volcanic eruption and is part of a Miocene series of rocks called the John Day Formation, near Biggs, Oregon, USA. It is a decorative stone used for jewellery and trinkets.
The Church of St. George or Bet Giyorgis in Lalibela, Ethiopia is cut into the shape of a square cross, and visitors enter the church via stairs cut down into the volcanic rock. Monolithic churches were carved out of the ground to which they are still attached. Eight hundred years ago the Ethiopian King Lalibela had a divine vision to carve a new Jerusalem from volcanic rock.