I've finally got a lot of the Red Centre pictures uploaded. Not labelled yet, but you can view them. Tom took a lot of the Coober Pedy pics. He was more than fascinated by this town carved out of the dirt, and in many cases, built into the ground. The temperature underground is stable at 23 or so degrees Celcius. That way it's warm in the cooler winter, and cool in the hotter summer. Most of the activity in this area is tied to opals. People dig deep pits to discover the location of the "colour".
The inland seas left mineral deposits when they retreated and dried up. The minerals were then compressed into silica spheres which shine in many beautiful colours when exposed to light. (The explanation is much more complicated than that, but we could also find pieces of gypsum which show the long, slender spheres.) The rock has to be sliced and polished to allow the colours to be refracted.
Very recently, the town built gutters and curbs on the main streets, but other than a few main streets, everything is still unpaved. The kids were finding "colour" on bits of gravel that lay on parking lots. We spent the night in a hostel that was dug into the ground. Not good if you feel claustrophobic, but more than cozy, as the night cooled off significantly. David and Sonia prepared a delicious evening meal and hot porridge in the morning to get us going on our early start to make it to Yulara while it was still light enough to set up our tents.