Another nice stone found on a North Otago beach, near Kakanui, sometime during the last 18 months and finally polished in December 2021:
It is 4.5 cms long, 4 cms wide and 2 cms deep, a good size. I tumbled the stone initially in 400 grit for 10 days then in 600 grit for 14 days. I have recently been adding this 600 stage especially for jaspers. It then spent 14 days in tin oxide polish and was burnished in borax for three days. This type of jasper can be found on many beaches in New Zealand, and it usually polishes very well:
I used two main sources to confirm my strong suspicion that this is most likely brecciated jasper. First, I referred to Patti Polk’s book, “Collecting Rocks, Gems and Minerals” (3rd edition, published in 2016). Polk is a notable agate collector from the USA and her book has a well-illustrated section on jasper. One page is on brecciated jasper and some of the examples shown there confirm the identity of Stone #8:
Secondly, Wikipedia turned out to have a couple of useful photos in its entry on “Jasper”:
I have found a small number of brecciated jasper stones at Kakanui before and one is featured on the January page of my 2022 TumbleStone calendar:
Stone of the Day #9 is here. The Index to the January 2022 Stone of the Day Series is here.
Great stones. I haven’t used my polisher lately but you make me want to do so. I’m a lesser rock geek but geek nonetheless.
Thank you for your positive feedback.