Amygdaloidal Basalt with Epidote
Amygdaloidal basalt, showing instead, gas vesicles (bubbles) with epidote crystals as opposed to the usual quartz and calcites normally expected. Specimens come from the Isle of Skye and are available in various sizes, each rock will come in a card tray with an information label.
Amygdaloidal basalt is a variety of lava which has crystal infilled former gas vesicles often appearing as small white spots in the otherwise black finely crystalline basalt. The infill usually occurs as a secondary process. Mineral rich volcanic fluids or ground water deposit minerals such as quartz, calcite & sometimes zeolites in the solidified gas bubbles. However, in this case, the mineral which has formed within the gas bubbles is epidote, which is easily identifiable due to its dark green colouration. These particular samples come from the Isle of Skye and the epidote variation is a little rarer than the standard amygdaloidal basalt. Each specimen is supplied in a labelled card tray with optional sizes.