Gemmy, Emerald-Green Vivianite Crystals - Brazil

This is a gorgeous cluster of blue-green vivianite crystals, collected from the Cabeça do Cachorro Claim along the Cauaburi river of State of Amazonas, Brazil. The crystals are in good condition and exhibit a beautiful luster and color. They are still attached to a piece of botryoidal siderite encrusted, phosphatic matrix.

It comes with an acrylic display stand.

Vivianite is a hydrous iron phosphate mineral that appears in flat, prismatic crystals. This mineral is highly sought after for its deep teal coloring and crisp translucence. It looks like a mystical glass that may be found in a fantasy movie. While it is commonly an iron phosphate mineral, occasionally the iron ion maybe substituted for magnesium, calcium, or manganese.

Even though it is prized for its color, it does not begin its existence in a glassy blue-green state. Vivianite is originally completely clear. However, when exposed to light, the crystals begin a chemical reaction, converting the iron(ii) ion into the iron(iii) ion. When this happens the mineral gradually shifts to a blue and then into a blue-green and keeps deepening in color until it is almost opaque black. Vivianite will color shift at different rates depending on the amount and intensity of the light it is exposed to. Therefore it is never truly stable, but as long as its exposure time is limited it should remain a consistent color for quite some time.

The highest quality vivianite crystals typically appear within hydrothermal veins. However, vivianite is occasionally found in association with fossils, especially lining the shells of bivalves or gastropods. A mummified steppe bison discovered in Alaska was coated in blue-green vivianite crystal oxidation, lending the specimen the nickname "Blue Babe".
FOR SALE
$195 $175
DETAILS
SPECIES
Vivianite
LOCATION
Cabeça do Cachorro Claim, São Gabriel da Cachoeira, Amazonas State, Brazil
SIZE
Entire specimen: 4.9 x 2.5"
CATEGORY
ITEM
#218183