6 wt% copper, which is associated with copper-tin minerals such as stannite
Tin does not occur naturally by itself, and must be extracted from a base compound, usually cassiterite, stannite
, cylindrite, franckeite, canfieldite, and teallite.
The short-prismatic, face-rich, vaguely barrel-shaped siderite crystals, reaching 2 cm, are gemmy and yellow-brown, and rest on brassy yellow, discoidal crystals of pyrite pseudomorphous after (a first generation of) siderite, with lustrous black crystals of stannite
to 3 mm around the points of attachment--making for impressive toenail and small miniature-size specimens.
21 The mineral stannite
contains copper, iron and which other metal of which it is an ore?
Appearance of a grey film indicates dissolution as stannite
and must be avoided.
The place in question is an entirely landlocked, mountainous, somewhat mysterious-seeming country which boasts a long mining history and has a secure reputation for turning out world-class specimens of--oh, let's see--metallic species (andorite, pyrarygrite, stannite
, franckeite, cylindrite), other primary ores (cassiterite, ferberite), and glamorous phosphates (phosphophyl-lite, paravauxite, vivianite, ludlamite) such as we have long admired and lusted after.
As in all books, there are some errors; for instance, the stannite
pictured in the book is really a sphalerite.
X-ray diffraction analysis indicates that the replacing substance is a mixture of chalcopyrite, pyrite and a mineral close to stannite
Mathias had set out a few "new" finds, and was especially proud of a specimen of andorite with associated zinkenite and stannite
from the San Jose mine, Oruro, Bolivia.
What is surprising is that some of the gray stannite
twins are also quite lustrous and well-formed, and these reach 4.
It is the type locality for five mineral species (vauxite, metavauxite, paravauxite, sigloite and jeanbandyite) and has also produced some of the world's best specimens of stannite
, cylindrite, monazite, bismoclite, and other species.