I've found Madagascar Yellow Opal a challenging stone to facet. It's soft so it's very brittle. Chipping a girdle can be done with ease. It's also sensitive to heat. On removal from the dop it can chip or break also. But I will continue to learn to cut such stones as they not often faceted. Being not entirely clear, more a semi translucent stone makes it also challenging find clean clear pieces without veils, cloudiness or inclusions. But I won't let all these difficulties get the better of me. I'm determined to someday cut a nice yellow opal. Hopefully it will come from this 147 carat piece shown in this photo. Anything over 4 carats I would consider to be a large cut, considering Opal is a lighter gem in density.