MINERAL OF THE QUARTER By Ronald L. Parker Senior Geologist, Borehole Image Specialists, 5650 Greenwood Plaza Boulevard, Suite 103 Greenwood Village, CO 80111 | ron@bhigeo.com
STILBITE One Zeolite Rock-Star
»»CONTINUED ON PAGE 31
Stilbite is one of the most common members of the zeolite family of minerals. Here, pinkish splays of stilbite appear to thicken away from a radial central point to form the diagnostic “bow-tie” or “wheat sheaf” crystal aggregates. Stilbite commonly co-occurs with other zeolites, in this case, pointy heulandite (top center). The light green pseudo-cubic apophyllite makes this an especially pleasing specimen. Photo by Ronald L. Parker
OUTCROP | October 2019
30
Vol. 68, No. 10 | www.rmag.org