Ocos Geodes
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Many names have been given to geodes throughout the
world, but none so fitting as the Ocos Geode (some say
these are named for their source, the Orinoco River in Brazil,
others believe it came from the Portuguese word for
"hollow," you decide...)
Ocos formed some 130 million years ago in
basalt amygdules (a formerly open vesicle which has been
filled with a secondary mineral(s) precipitated from low temp
ground waters which penetrated into the rock). Over the
years the basalts have been weathered away and left behind
small geodes in what is now called cascalho, a dark reddish
brown soil in the Serra Geral Formation.
Ocos are mainly found in the 3000 ft elevations of the Tres
Pinheiros (Three Pines) region.  The geodes are normally
removed from the basalt by hand (which can be difficult
because their skin or outer shell of chalcedony is relatively
thin and often rope-like in formation). The Ocos are then
taken back down the steep mountains in burlap sacks or
buckets on horseback or by pack mules to the town of
Soledade to be cut and polished.
Thin shell Ocos called "casa fina" command a higher price,
but display less of the famous wavy or flame like patterns on
the rim. Ocos size is usually small (1-3 inches)
When cut, Ocos display brilliant drusy quartz linings on tan,
grey, brown or black shells with white waves or flames. Many
Ocos have inclusions in the quartz, rarely amethyst.

Ocos
Geodes

aka

Ochos
Occos
Item # 1-OGP11160010
Polished Ocos Geode Pair
$10.00
Beautiful black, white and clear swirls on the polished
edge with well formed clear quartz crystals with black
inclusions.
This pair weighs 20.5g
Item # 2-OGP11160010
Polished Ocos Geode Pair  
$10.00
Clear quartz with black and white inclusions in the
polished edge with well formed quartz crystals in the
vugs.
This pair weighs 28g
Item # 3-OGP11160010
Polished Ocos Geode Pair
$10.00
Grey, white  and clear wisps with a touch of mahogany
on the polished edge with well formed quartz crystals in
the vugs.
This pair weighs 30.5g
Item # 4-OGP11160010
Polished Ocos Geode Pair
$10.00
Clear, tan, white, grey and clear wisps on the polished
edge with well formed quartz crystals
This pair weighs 36g
Item # 5-OGP11160010
Polished Ocos Geode Pair
$10.00
Tan, mahogany and white swirls and wisps on the
polished edge with well formed quartz crystals in the
vugs with black inclusions.
This pair weighs 30g
Item # 6-OGP11160010
Polished Ocos Geode Pair
$10.00
Tan, black, grey, white and clear wisps on the polished
edge with well formed quartz crystals in the vugs.
This pair weighs 22.5g
Item # 7-OGP11160010
Polished Ocos Geode Pair
$10.00
Grey and clear band around a polished crystalline
center with touches of mahogany on the polished edge.
Vugs have quartz crystals.
This pair weighs 33g
Item # 8-OGP11160010
Polished Ocos Geode Pair
$10.00
Item # 9-OGP11160010
Polished Ocos Geode Pair
$10.00
Item # 10-OGP11160010
Polished Ocos Geode Pair
$10.00
Tan, clear and white swirling lines on the polished
edge. Vugs have druzy quartz crystals.
This pair weighs 18.5g
Item # 11-OGP11160010
Polished Ocos Geode Pair
$10.00
Item # 12-OGP11160010
Polished Ocos Geode Pair
$10.00
Grey and clear band around pinkish fortification lines
on the polished edge. Vugs have druzy quartz crystals
with a pinkish tint.
This pair weighs 30g
Item # 13-OGP11160010
Polished Ocos Geode Pair
$10.00
Tan, white clear and black mottling around
crystalline quartz center vugs.
This pair weighs 36.5g
Item # 14-OGP11160010
Polished Ocos Geode Pair
$8.00
Black, white and clear swirls lines on the polished edge. Vugs have druzy quartz crystals.
This piece had natural fracture which broke off during cutting and polishing.
Left click photos for larger view
This pair weighs 33g
Item # 15-OGP11160010
Polished Ocos Geode Pair
$10.00
Tan, clear and white lines on the polished edge. Vugs
have druzy quartz crystals with goethite inclusions.
This pair weighs 27g
Item # 16-OGP11160010
Polished Ocos Geode Pair
$10.00
Tan, white and black switls on the polished edge
surrounds a crystalline center.  Vugs have well
formed  quartz crystals.
This pair weighs 30g
Item # 17-OGP11160010
Polished Ocos Geode Pair
$10.00
Black, white and mahogany lines on the polished edge.
Vugs have druzy quartz crystals.
This pair weighs34g
Item # 18-OGP11160010
Polished Ocos Geode Pair
$10.00
Tan, white clear and grey lines on the polished edge.
Vugs have druzy quartz crystals with goethite inclusions.
This pair weighs 27g
Item # 19-OGP11160010
Polished Ocos Geode Pair
$10.00
Black, clear and grey mix on the polished edge. Vugs
have druzy quartz crystals with minor goethite inclusions.
This pair weighs 19g
Item # 20-OGP11160010
Polished Ocos Geode Pair
$10.00
Stunning shades of grey and white surround this
beautiful clear crystalline center with vugs displaying
well formed quartz crystals.
This pair weighs 20g
Grey, black, white and clear swirls around a polished
crystalline center with touches of mahogany on the
polished edge. Vugs have quartz crystals.
This pair weighs 34.5g
Grey, black, white and clear swirls around a polished
crystalline center with touches of mahogany on the
polished edge. Vugs have quartz crystals.
This pair weighs 20.5g
Tan, clear and white feathering lines on the
polished edge. Vugs have druzy quartz crystals,
some with dark inclusions.
This pair weighs 33.5g