FMF - Friends of Minerals Forum, discussion and message board

[Fiebre Verde]

From pink to burgundy red.
Compact aggregates of deep to very deep burgundy red scalenohedral crystals.
Metallic-bright, black manganite blades cover the manganite matrix.

[Fiebre Verde]

... and back to pink!

Scalenohedral 'wheat-sheaf' rhodochrosite crystals arranged in spherical aggregates on a manganite matrix.
Crystals have pale pink cloudy centers and red gem clear tips.

[Tobi]

Quite strange to see something not green in your thread ;-)
But the specimens and photos are good as well!

Tobi

[Fiebre Verde]

[chris]

Hi,

Didn't know you had turned red lately. Great rhodo & always a pleasure to have a look at some beryls. Looking forward the other ones.

Christophe

[Fiebre Verde]

[Fiebre Verde]

Another large cluster of intergrown crystals from the El Toro mine.
The orange-brown limonite cover makes the specimen look like if it was just recovered from the mine. And this is the reason why I had it inspected by several local dealers first.
The discovery of this pocket in 2008 had fueled the imagination of the local mineral craftsmen and at that time the demand had led to lot of fakes on the Bogota market.
This reached a point where some local dealers refused to take the risk of trading them.

Not sure how much of those 'high-risk' limonite covered specimens made it to the foreign market.
As far as I remember I haven't seen any of those specimens offered by internet dealers or at the main European shows (wasn't in Tucson).

[Fiebre Verde]

When present, rutile occurs as solid inclusions in the emeralds but is very rarely observed as an associated mineral.
A while back I posted some close-ups in a different thread to request some assistance on what could be that elongated crystal (4mm) with a bright metallic luster. The consensus was that it was very likely rutile.

Host rock is weathered black shale crosscut by a network of calcite veinlets

[Fiebre Verde]

Like those in Colombia, the Panjshir emeralds are formed through a hydrothermal process.
Host rock is a metamorphic schist that has been subjected to intense hydrothermal alteration.

[Fiebre Verde]

La Pita specimen with large calcite crystals.
Host rock is black shale.

[Fiebre Verde]

White lustrous calcite is never easy to photograph and this large specimen is no exception.
There are a couple of grey dolomite crystals scattered around.
Also some remnants of the black shale host rock can be observed in the back.

[Fiebre Verde]

Peruvian red this time :-)

Compact aggregate of burgundy-red rhodochrosite scalenohedrons associated with colorless rounded fluorite and quartz on a goethite matrix.
Some of the rhodochrosite crystals have stepped faces which are poorly rendered in the last close-up images.

[Fiebre Verde]

Back to Cunas, one of the most prolific Colombian emerald mines in the past 10 years.
Note the lustrous dark grey dolomite rhombs. The thin long emerald crystal (20mm) is doubly-terminated.
Host rock is black shale.
Snow-white acicular sprays of an unknown mineral are visible in the last close-up image.

[Fiebre Verde]

A rarity from Coscuez because of the... calcite!
Tabular calcite is not common and I have only seen this crystal habit in the Western Belt - mainly in Coscuez.

Calcite is dusted with what looks like whitish goethite.
This specimen is from the early 00's. Host rock is black shale.

[Fiebre Verde]

Another matrix specimen with no associated minerals other than elongated beryl crystals.
And another illustration of the incredible variety of specimens from the Chivor district, as opposed to Muzo, Coscuez, or La Pita.
The shorter crystal is fractured which suggests that it grew first.
Host rock is a weathered black shale.