Bournonite (“cogwheel”) on matrix blue-green This material is rarely seen

This material is rarely seen in today's market and this particular specimen is at least 35 years old

all the way to tan / brown Siderite at the other end of the series

there are a few rough spots here and there

this attractive three-dimensional “mound” of black “Marmatite” Sphalerite is comprised of sharp

Zircon crystals are not terribly common from around Mogok

Bournonite (“cogwheel”) on matrix blue-green This material is rarely seenFinding a fine quality "cogwheel" such as this on matrix from Machacamarca is not common, and the photos honestly do not do this piece justice as it is much more eye catching in person. This piece features a few attractive "cogwheel" twinned crystal groups of Bournonite with superb luster sitting atop a matrix of micro Pyrite, Quartz and Sphalerite. The "cogwheels" feature dozens of discreet, striated "cogs" that form the edge of the fairly thick