Incredible colors! Igneous rocks formed from lava flows of the Archaean era (>2,700 million years ago) are often found to contain disequilibrium-textured crystals characterized by spherulitic, branching or dendritic morphologies that occur in layers near the flow surface.
Rainbow Eucalyptus" Hana, Maui, Hawaii The unusual phenomenon is caused by patches of bark shedding at different times. The different colours are therefore indicators of the age of the bark: Freshly shed outer bark will reveal the bright green inner bark. This darkens over time and changes from blue to purple and then reaches orange and maroon tones.