‘Transitional nodules’, as Paul Colburn named them, are presented in this set.
Most of the backs of these cut eggs show a wrathy surface. Some (visible) spherulatic cristallization took place… These stones do not look like the characteristic thundereggs though. Seems to me that many pieces of rockrubble has been ‘eaten’ by a lava flow. After that irregular spherulatic cristallization took place and therfore the stones may be called thundereggs. The term transitional nodules is discussed here.