Acquisition of the month: Japanese twin quartz
I recently added a fine specimen of a Japanese-law quartz twin to my collection from the Ambolo Quartz Mine in Madagascar. This crystallographic peculiarity is…
Story behind the stone: sulfur from the Ijen volcano
Recently a friend gave me a beautiful piece of sulfur, he asked me if I knew where it came from, “Indonesia” I said, “Yes!” he…
Sphalerite or not? Part II
In my earlier article sphalerite or not? Part I you could read, which I told about some polished towers of “sphalerite” that I analyzed for…
Typical geodes
In this article, we explore the fascinating world of geodes, hollow spaces in rocks filled with beautiful minerals such as chalcedony, agate, and quar…
Progress is impossible without change
New developments are piling up at Stack of Stones. Today, I am pleased to delight you with the first monthly ‘Written in Stone’ newsletter on…
Fact or fable? – Septarian concretions originate from deceased animals
Septarian is a special stone that attracts attention with its unique appearance. Moreover, an interesting story circulates about the origin of septarian dating back to…
Sphalerite or not? Part I
Quite some time ago I received from one of my students who also sells stones a number of polished towers of “sphalerite.” At least under…
