During a fossick on a beach near Kakanui (North Otago) on 6 March this year, I met Barb and Derek (see the end of the Post February-March 2022 Fossicking Trip: Stone of the Day #24, Kakanui Multi-Coloured Quartzite; for an introduction to the Kakanui beach, see this Post). They regularly walk this stretch of beach, picking up rubbish as well as an occasional stone. Barb had just found a small smooth gray quartz stone and I offered to tumble-polish it for her. Derek found a small beach agate while we were chatting – he gave it to me and I tumbled it in the same batch as Barb’s stone, which included a number of Kakanui stones.
After tumbling the stones in 400 grit for a couple of weeks, they spent 11 days in tumble polish (tin oxide) and five days in a burnishing borax tumble. I will put them in the mail tomorrow to Barb and Derek in Oamaru, along with 20 other small Kakanui stones.
Barb’s grey quartz stone has emerged very smooth from the process though some internal “cracks” are able to be seen. Derek’s beach agate has lost some of the interesting white weathering patterns on its surface, with only a small squiggle left on one side. The other 20 Kakanui stones were tumbled in the same batch, many of them being quartzites, some with tiny clear quartz crystals in them, as these three below have.
Stones 1 to 5 are also likely to be quartzites (see photos below). As with many small stones when being tumble polished, decisions have to be made about how smooth to get them before the final polish. Sometimes, getting them completely smooth may may the stone very small. In order to retain their interesting patterns, some small holes or rough patches may end up remaining.
The following five are also likely to be quartzites. The last of these, Stone 19, is a particularly unusual one for its colour and the number of clear crystals in it.
Stone 12 (see below) is another quartzite while Stones 11, 13 and 15 are likely to be varieties of quartz, with Stone 15 having some interesting moss-like inclusions:
The three remaining stones are jaspers, which are often a challenge to polish:
Anyone who spends time on beaches understands how much rubbish, especially plastics, can be found there. Anyone who picks it up to remove it from the beach is well worthy of our encouragement and support.
