Fluid inclusion in Quartz

This image was taken of a tiny portion of a rock thin section through a Zeiss petrological microscope using a small CCD camera. It shows the class 'Fried Egg' style fluid inclusion - a cavity that was left behind as the crystal formed which contains a bit of the original fluids that the crystal grew from. This example shows a small CO2 gas bubble floating in the fluid in the cavity. The fluid itself is divided into two immiscible portions - aqueous brine and CO2. These inclusions can be studied to determine the environmental conditions present when the crystal was formed. Sometimes these inclusions can also contain small solids - other crystals that have also been trapped in the cavity.

This section was taken from a fenitised rock collected from the Chilwa Island volcanic complex in Malawi. It is country rock that has been extensively altered by hydrothermal fluids during and since the original activity.