Here we have a large display-quality specimen, with a thin sheet of brilliantly colored opal overlaying the matrix. I cannot recall seeing for sale any true boulder opal like this from Brazil, and when I bought the piece from an older collection I was admittedly skeptical. But now I see there are photos on MINDAT, and an Aussie friend confirmed that yes, some of these really did come out in this quality from Brazil - though not many, and few in quality.