FMF - Friends of Minerals Forum, discussion and message board

[Firmo Espinar]

Congratulations Tobi.

They are many contributions.

[Jordi Fabre]

[Jordi Fabre]

Barcelona 13/07/2018

One of the things that helps to better understand the atmosphere of the Shows are the reviews of the local newspapers. Thanks to the help of Pina and Gérard Schneller we can see the vision of the St. Marie Show of the local newspaper DNA.

This time the quality of the scanner is not the desirable due some technical issues. In case you really want to read well these files you can go to the web page of the DNA and find them there.

Thanks Pina and Gérard!

[Jordi Fabre]

Ste. Marie has already finished for me, I hope others are still encouraged and publish more photos about this so hot edition. I remember once more that in the Spanish side there is a lot of information and images (6 pages and over 500 images at this time)

Ste. Marie is like a kind of anchor with the past. Is the third most important Mineral Show in the world and one can find there details as endearing as the ad below that could be placed on one of the billboards of the "Piscine" almost as much as the minerals in the veins of the Vallée of Sainte-Marie-aux-Mines!😁

I still have you in my heart Ste. Marie

[Roger Warin]

Hi,
Gachala (Colombia) is not only famous for its emeralds, but also for its pyrites.
Two twinned pyritohedrons (interpenetration) also known as iron cross twin. Twin axis [001].
Seen at Sainte-Marie-aux-Mines show (2019).

[Roger Warin]

Hi,
Wiluite crystallizes in the tetragonal system and occurs in well-formed crystals with good external form. It is isostructural with vesuviante. Formerly, it was regarded as a variety of Vesuvianite (Fabre's specimen).

[Jordi Fabre]

[Roger Warin]

Jordi,

Yes, I think also it’s a calcite, with the hexagonal prism terminated by the pinacoid. This habit is called “kanonen spath” in Germany.
This habit is frequent at St Andreasberg. Correct Tobi?

[Tobi]

The Sagrada Familia made of calcite - great :-)

[Jordi Fabre]

[Roger Warin]

Here are 3 examples of Kanonenspat from the St Andreasberg locality, not seen at the Ste Marie Show.
Height: 5 cm.
The cleavage planes are visible.

[Roger Warin]

A beryllium phosphate NaBePO4
in the SMM Show 2019.

[Jordi Fabre]

[Roger Warin]

SULFOSALT MINERAL SPECIES

Bournonite PbCuSbS3 is a sulfosalt mineral species, thioantimonide of lead and copper.
Bournonite is usually twinned to give some crosses or yet gear wheels.

Pyrargyrite is a sulfosalt mineral consisting of silver sulfoantimonide, Ag3SbS3 known also as dark red silver ore.

Pyrargyrite is isomorphous with the corresponding sulfoarsenide known as proustite or light red silver ore.

The prefix thio-, when applied to a chemical, such as an ion, means that an oxygen atom in the compound has been replaced by a sulfur atom. (Greek root).
The prefix sulfo is similar (latin root).

[Roger Warin]

TSAVORITE versus EMERALD

Tsavorite is a chromiferous and vanadiferous variety of the grossular garnet of formula Ca3Al2 (SiO4)3.

Like the green emerald, tsavorite is green too, but warmer green, with a touch of yellow. But yet the beautiful emerald sometimes has, at the bottom end, some big flaws. On the one hand it is brittle, but it can be garnished with whitish gardens sometimes too important, altering its hue.

What are the qualities of tsavorite? It is a garnet, so it has about the same hardness as the emerald, but its tenacity is superior. It therefore has excellent mechanical qualities. As for its color? It seduces too. Its slightly gilded green color sometimes has deep and saturated hues. They delight the eye. The color can be "electric". It becomes a real killer. However, its dimensions are often limited. It has other advantages such as clarity and absence of cleavages. Unlike the emerald which does not get smaller in size because of its low tenacity, tsavorite allows this size which is currently very popular in modern jewelry.

Tsavorite also has for it, the spices of novelty and originality. Its gems do not require all the treatments of ordinary emeralds.
Emerald is not relatively uncommon, unlike tsavorite. The jewelery industry is calling for a steady supply of gems. The tsavorite trade can only be successfully supported if constant availability is ensured. This is not the case currently, despite the many qualities of this new gem. The synthesis could remedy this situation.
It's my opinion…