In 1999, I had the good fortune of discovering a world class occurrence of heulandite and mordenite near Challis, Idaho. After prospecting it, and doing small scale specimen mining for a couple of years, I made arrangements with my friend John Cornish to mine it for heulandite and mordenite specimens.
In early 2004, I sold this claim to John who will be the mining it for specimens for many years. You can see him and these fabulous specimens at the Denver Gem & Mineral Show in September, the Tucson Show in February, and several shows in the Pacific Northwest each year.
In the same area, two years later, I discovered the source of the rare quartz pseudomorphs after apophyllite. These were known because Norm Radford had found one specimen as float in the area more than 30 years ago. We explored this occurrence in late May 2004 with a trackhoe, and recovered more excellent specimens of these rare pseudomorphs with some unsual platy and prismatic calcite crystals.
Below are links to three articles, one on the discovery of the Rat's Nest deposit, one on mining operations in 2003 and one on exploration of the pseudomorph locality in 2004.
A small cavity lined with heulandite-Na and a cluster of quartz crystals. From the matrix which has the large cavities lined with the pink heulandite-Ca crystals.
A very nice large heulandite geode. The large heulandites are the species heulandite-Ca. The matrix contains small vesicles lined with orange to red-orange crystals of heulandite-Na, and sometimes quartz, as in the specimen in the photograph to the right.