While we were in Queenstown, we stayed with friends who have a house right on the shore of Lake Wakatipu. Imagine looking out at this lovely view from your living-room window every day!
Early in the morning we followed the short track down to the beach and I was amazed to find that the frost was right down on the stones along the shoreline.
Where the water had defrosted them, the wave-worn schist pebbles were the most wondrous shades of white, cream, orange, blue-grey, and green.
I brought some home with me. Predictably, I like the green one best. I wetted them to bring out the colours, but I think they would tumble up and polish well. The layered appearance show that they were originally sedimentary - laid down in stillish water - but the crystaline form (I can see little twinkles of quartzite crystals) and the wavy veins, tell me that these rocks have been under huge pressure and the soft sediments have been compressed so hard they heated up and metamorphosed - changed their molecular structure - into what we call schist (a word that comes from the Greek for 'split'). It's mined locally and when split it is popular house-cladding material around Queenstown.