Approximately 3x lifesized, 56 stacked images. Backlit. There is not much point in focus stacking something relatively flat like this - but moving the focal plane into the semi-transparent rock slice does seem to bring out some details and structures that enhance the image. And stacking also spared me from having to align the stone to the camera's focal plane.
This portion of the crsytal was in a recessed "stair step" structure, which was very difficult to light. I wound up abondoning the use of flash and instead shot with ambient lighting. This resulted in a very long shutter speed of about 1/2 second for each image. Made with a Pentax K01 and reverse mounted SMC K 24 f3.5. 70 stacked images.