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[Fiebre Verde]

Let's start this long Colombian journey with a typical specimen from Peñas Blancas.

Host rock is brecciated and matrix is covered by large areas of iron-stained and creamy calcite.
Emeralds are slightly bluish green and possess the typical velvety appearance of this locality. Some of the crystals have pits and cavities which is another characteristic of Peñas Blancas.
This specimen shows 2 distinct areas: The area where the emerald is fully crystallized and the area where it is not. The latter material is locally called "moralla".

[Josele]

Nice start, a good piece, proper photo, detailed comments, let's go!
Thanks for sharing.

[Fiebre Verde]

Thanks Josele! More to come...
Gérard

[Fiebre Verde]

Since the Peñas Blancas locality is a bit overlooked by collectors, I thought I could post another interesting specimen.
Unlike the previous specimen, the main crystal has a very light bluish-green tone.
The 2cm long intergrown crystals give the illusion that it's one bi-terminated emerald.

[Fiebre Verde]

This is a veinlet from the La Pita mining area I managed to smuggle a few years back.
The host rock is a black carboniferous shale, typical from the locality.
The main vein should have been close by but it was not for sale...
Fracture was not wide enough to let the emerald/pyrite crystals grow.

[Fiebre Verde]

La Pava is one of the many mines of the famous Muzo mining district.
Muzo emeralds are well-known for their beautiful dark green color in association with crystallized pyrite.
This specimen features a light yellowish-green emerald and ... no pyrite - just white calcite and the host rock (black shale).
Note the contact area on the basal pinacoid termination (last photo).

[Fiebre Verde]

Another specimen from La Pava with a lighter bluish-green crystal than the previous one. This almost flawless emerald has a pyramidal termination and comes with white calcite - no host rock. It has a beautiful vitreous luster which is typical of some pockets of this mine.

[Fiebre Verde]

A classic setting for Colombian specimens - an emerald crystal perched on a white calcite rhomb/scalenohedron.
First photo was taken using LED lights.
The 2 last photos were taken under daylight. Yellow is clearly the secondary color which is a characteristic of Muzo emeralds.
The emerald termination is not flat and looks like a contact area.

[Fiebre Verde]

A classic association from a classic locality. Emerald & Quartz from Muzo mining district.
There are 2 emerald intergrown crystals plus a smaller one on the side.

[Fiebre Verde]

This specimen is interesting because the emerald crystallization has an occurrence of aggregate type formations with multiple individual terminations, specially in the central part. The emerald formation is literally crisscrossing the milky calcite matrix. A few patches of black shale host rock are also visible.
These aggregate type formations are very frequent in Coscuez.

[Fiebre Verde]

Another unusual specimen from the Cunas mine in La Pita mining district.
Emerald material is low quality (moralla grade) with very little crystallization (see last close up image).
The emerald aggregate shows a clear bedding pattern and has been fractured perpendicularly in various places. Some fractures were filled up by white calcite.
The minerals in the background are grey calcite - no host rock.

[Fiebre Verde]

A classic specimen from the La Pita mining district with dark grey calcite.

[Fiebre Verde]

This specimen from the Coscuez mining district comes with one single crystal with a complex termination combining flat basal pinacoid in the outside part and multiple individual terminations in the inside part (see last close ups)
Matrix is typical from this locality e.g. black shale in combination with grey calcite and a rust colored layer of iron oxide.

[Fiebre Verde]

Classic Coscuez specimen combining white and grey calcite on black shale host rock.
These sharply formed white scalenohedral crystals of calcite are also frequent in the neighboring La Pita mining district.

[Fiebre Verde]

Another beautiful specimen from Coscuez.
Emerald patches are scattered all around a milky-white calcite matrix.
Also fully crystallized translucent calcite aggregates are present in some areas.
But the most significant feature of this specimen is the occurrence of several emerald aggregates which is one the significant trademarks of Coscuez.
In this specimen they either take a step-like appearance or a tabular appearance.
That's the magic of Coscuez emeralds... when they are not sent for cutting!