- Chrysocolla in Tyrolite With Clinotyrolite
- Miniature, 4.0 x 2.6 x 2.6 cm
- San Simon Mine, Huantajaya, Iquique Province, Tarapac
- Ex. Philadelphia Academy of Natural Sciences
These specimens (PAS-187 to PAS-189) were presented to the academy by the famed Dr. Domeyko in the late 1800s, who did much work on the rare minerals of Chile and Argentina. Regardless of the chemistry, the specimen has merit as a display piece of beautiful copper combinations from Chile. This piece has beautiful, powder-blue chrysocolla forming as a thin carpet in the few hollow vugs within nearly solid tyrolite! It is a beautiful miniature, trimmed by me from specimen PAS-187 above. On analysis by modern equipment, the matrix material shows to be tyrolite, clinotyrolite, and possibly other related species admixed (X-RAY and powder, Bart Cannon's lab, 2008), However, apparently the official mineralogy of tyrolite classification is confusing and has changed over time. Clinotyrolite is often considered a species by many people, though without IMA approval. I quote Mindat.org's page on the matter verbatim to make sure I do not mistakenly convey the science: Since it is well-known that also carbonate-free varieties of tyrolite exist, "tyrolite" may actually represent two or more minerals/polytypes. At least two monoclinic polytypes of tyrolite are known (Krivovichev et al., 2006); one of them seems to be identical to "clinotyrolite.." Note that this is the first report of the locality to Mindat.org for tyrolite occurrence, but it is likely that this rare species is present on other old specimens of "chrysocolla" from Chile.