Gleba mentions a blue pigment deposit near abandoned mineral springs in Hopkinton, Mass. One Joel Norcross “discovered” the springs in 1815 while repairing his sawmill after a tornado and electrical storm (though surely they were known to the Native Americans who had been in the area for millennia). An analysis of the water from the…

It’s been a busy couple of weeks: a natural pigment workshop at what used to be Harvard’s Fogg Museum and is now part of the Harvard Art Museums complex; an investigation into a surprising source of red ochre pigment; and the first alchemical experiment of this art adventure. The workshop was presented by the very…

I expect some people will be relieved to know that I am not going to try to convert yellow ochre into red in my kitchen right now. The minimum temperature required is 500°C, not 500 °F. Or 200 °C. Or 300 °C. It’s just not that clear. I need to do more research to discover…

Much to my amazement, when I searched “ochre Massachusetts,” Google gave me a useful result, an abandoned “paint mine” active in the 1860s, where a natural deposit of ochre had yielded a yellow-brown pigment “of superior quality.” This very specific information was a great help to a neophyte pigment hunter who could reliably identify only…