Pickeringite was identified by Bandy (1944) as a post-mining formation in old galleries, together with halotrichite
The larger tabular marcasite crystals are sometimes coated with secondary minerals such as natrojarosite, rozenite and halotrichite
, and tend to crack after a few years in a collection.
Associated minerals are: coskreaite-(Ce), levinsonite-(Y), melanterite, halotrichite
, picketingite, apjohnite, epsomite and other hydrated sulfates.
Amazingly, Jones and Novak were able to salvage many of the specimens by teasing the halotrichite
hairs up again with a comb and trimming them carefully with scissors.
forms silky white to yellowish fibrous masses and free-standing acicular crystals with no visible faces on terminations (Fig.
Fast-growing fibrous masses of pickeringite and halotrichite
are common in many of the old workings at Cerro Rico.
1-mm lemon-yellow flakey crystals associated with other sulfates including halotrichite
, melanterite, roemerite and voltaire.
They have grown in a pyrite-chlorite matrix with capillary white halotrichite
and fibroferrite (?
Typical minerals formed under these conditions are water-soluble sulfates such as chalcanthite, melanterite and halotrichite
, along with other more insoluble minerals such as malachite and chrysocolla.
occurs in an oxidized zone of the Brick 2 as minute, white, fibrous and acicular crystals.
Some joint surfaces of bleached and altered siltstone exposed at coordinates 19500N,22500E on the 5,075 bench locally exhibit thin coatings to 2 cm across of pale olive-green vanadiferous halotrichite
was observed on a single specimen as radiating acicular tufts within a cavity in massive barite, associated with anatase.