This stone was polished last month, having been found on Birdlings Flat over a year ago:
I initially thought it was a quartzite. The Stone of the Day Series in Level Four included six quartzites: Stone Two, Stone Nine, Stone Twenty, Stone Twenty-Seven, Stone Twenty-Nine and Stone Thirty.
As I mentioned in a previous Post, A quartzite starts off as a quartz-rich sandstone, a sedimentary rock that is grainy and feels like sandpaper. When the sandstone is exposed to high temperatures and pressures, the hard glassy metamorphic rock of quartzite is formed. Quartzite’s wide variety of colours are a result of minor amounts of impurities being incorporated with the quartz during the process of metamorphism.
However, the close-up images of Stone 6 of Level Two do not reveal the grains I would expect of a metamorphic quartzite but rather a set of crystalline structures closer to quartz itself.
It is only when looking at such images that the complexity of the stone can be appreciated – the various veins running through it, different inclusions, small iron stains, darker and lighter patches:
