In this post I am going to write about modified fluorite crystals. It is not going to be an static post, so each time I come across a nice modification, or I wonder about which type of modification has one of my specimens,… I will let you know through this post. Basically, I will post modified fluorite crystals from Asturias, but that is a lot because some of the fluorite localities in Asturias produce many lovely and different modifications.
As you probably already know, among thousands of different mineral species, fluorite is one of the most loved ones. I would dare to say it is the mineral that most collectors like! It can present lots of different colours, awesome and different mineral associations, crystallizations, corner modifications and so on!
Let’s start with one thumbnail fluorite specimens I sent recently to a good friend.
Please if you think any of the modifications presented here are incorrectly named, or just because you want to discuss about them, please feel free to let me know through email or just write a comment! Pretty sure there will be doubts in some crystals!
Today I just shot again a really weird modification on one fluorite specimen from La Viesca Mine, Asturias, Spain.
I found some of these modifications a few years ago in different pockets and it was a total surprise to me. I had never seen anything like this.
It reminds to the pattern when you separate two crystals but this is clearly not that case.
Madrid, the capital of Spain, is a real paradise for mineralogical museum enthusiasts. There are not many capitals in Europe where you can visit three outstanding mineralogical museums, but in Madrid you can!
Each one has high quality minerals and the three deserve a visit for sure. But they are quite different, so I am going to start writing about each one.
Museo Nacional de Ciencias Naturales
This is my least favourite out of the three, but still deserves time for a visit. The museum exhibits some quality minerals from old Spanish localities, but also many specimens of average or low quality, giving a not great overall impresion for a specialist in fine mineral specimens. On the other side, it can be very educative if you travel with children.
The mineral exhibits are not very well cared: you can see some cabinets with dust, poor labelling, etc.
Nonetheless, you can appreciate some excepcional minerals like a really large pyromorphite from El Horcajo, probably the largest I have ever seen. Or even a larger sulphur from Conil, both from true classic Spanish mineral localities!
You will find information about minerals and their uses, clearly aimed for a student level visitant. This is probably the most appealing mineral museum for children. But don’t get me wrong, fine mineral lovers will find some great mineral specimens as well.
In my opinion, if you are short of time, this museum is the one you can skip. You can not miss the others because they are just great classic mineralogical museums. Continue reading!
Museo Geominero del Instituto Geológico y Minero de España
It is also known by “Museo del IGME”. “IGME” stands for Instituto Geologico y Minero de España, which could be translated as Geological and Mining Institute of Spain.
The building itself justifies a visit. It was built between 1921 and 1940. The greatness of every hall takes you back to past times, when the Spanish mining industry was of great importance for the industrial development in Europe.
The museum shows one of the best sistematic mineral collections of the country with some provinces extremely well represented, for example, Madrid. The collection exhibited at the time of my visit did not stand out due to a large number of fine and aesthetic mineral specimens, although there were some, but because of the wide amount of minerals and localities represented.
Let’s say that the collection had very valuable specimens from rare Spanish localities but few of them ranked high in aesthetics if you compared them with worldwide localities. See below some nice specimens.
Other Spanish localities famous worldwide for their quality could be much better represented.
A visit to this museum is highly recommended. If you have enough time you will see hundreds of interesting specimens from Spain and overseas. If we add the quiet and classic atmosphere that surrounds the cabinets you will enjoy your visit for sure! Also, if you are lucky enough, you will see interesting temporary exhibitions which, from time to time, the curators of the museum assemble.
Another good point of this museum is its proximity to the next one…keep reading!
Museo Histórico-Minero Don Felipe de Borbón y Grecia
This is a very classic, cosy and tidy museum. Indeed, it is probably my favourite one out of the three of them. It is located in the XIX century building of the School of Mining Engineers of Madrid. Awesome building again!
One thing to keep in mind before a visit to this museum is that it is not open everyday. I think it opens always by appointment and also the first Sunday of each month (not sure about August), but it is best to give them a call well in advance.
The mineral and antique book collections inside the building are of great quality and importance for the country. Regarding the mineral collection, it tends to be better if we focus on classic, long ago closed Spanish localities, like Almaden, El Horcajo, Hiendelaencina, etc.
The mineral collection is also of great importance when we realize the quantity and quality of mineral specimens from less well known Spanish localities. See a few examples below.
The mineral specimens are well exhibited. They are inside beautiful old wood cabinets and lighting is good enough to enjoy the specimens. I remember two type of cabinets, some adjacent to the walls of the building and some free standing ones, all exquisitelymade. Hopefully, this will not change in the future as it is great to visit a museum that keeps the essence from past times. Of course, lighting could be better if new cabinets are set up but that would destroy the magic feeling it has now. Definitely you get the impression that the treasures of this museum are well cared!
As I said for the IGME museum, this one doesn’t offer either the visitor a huge number of worldclass specimens. Don’t forget that this museum was created, long time ago, with the main purpose of teaching. Is not an extremely showy museum to impress random people or to show just the most aesthetic and impressive specimens. It is more orientated to knowledgeable people who can appreciate rare mineral specimens, obscure localities from Spain and so on.
To finish this quick visit to this excellent museum lets show one of my favourite specimens. This is an exceedingly rare large cabinet sphalerite specimen from the Picos de Europa Mountains, Spain. The label says “Aliva”, which is an area in the central part of Picos de Europa famous for having produced the world best gem sphalerites. This specimen shows very defined crystal faces and poor translucency, which makes me think that it is probably from a rare old mine of Picos de Europa and not from the famous Las Manforas Mine in the Aliva area.
To finish of the post, another great specimen. I hope you like it and stay tuned because more will come about mineralogical museums!
As Wendell Wilson wrote recently in his High End Report Tucson Show 2014 “Color is King […]” and I think most mineral collectors will agree with his statement. Even more if we are speaking about fluorite specimens!
This is the first post about how to differentiate the fluorite specimens from Asturias, Spain. Today, I will focus in the wide colour range of fluorite crystals. In others posts I will speak about crystallization, mineral association, etc.
As you all probably know, fluorites crystals from Asturias, an small region in the north of Spain, rank between the finest cubic fluorites in the world.
There are some other fluorite localities in Spain, outside Asturias region, but they are not very well known for gemmy crystals and the quality is usually low. So we will focus only on the colour of the fluorites from the fluorspar deposits of Asturias, Spain.
Fluorite collectors from overseas usually get confused about the fluorite localities in Asturias. So many localities, so many mislabelled specimens. So this is a problem for a collector concerned with the origin of his fine fluorite specimens.
There are many obscure fluorite localities in Asturias but we will keep it simple for this post. To start with, I am going to let you know the four most famous localities nowadays. Each one produces quite different specimens, but sometimes is very difficult to assure the exact locality of a specimen.
1- La Collada . La Collada mining area comprises several fluorspar mines. Usually fluorites from La Collada range between blue and violet, but dull green hues are not specially rare. Zoned crystals are common. It is not very difficult to find blue and violet or light blue and dark blue in the same crystal.
General note for the green fluorites from La Collada: Dull green crystals are not rare, specially in some old areas; but vivid, bright greens, are exceptionally rare. Nowadays, green coloured crystals are rarely seen in the mineral specimen market.
Note: La Viesca Mine has been worked as an open pit and underground mine. It is inside of La Collada mining area. It usually produces from very light to very dark blue – violet coloured crystals. Purple colour is uncommon. Blues with a hint of green are scarce. Small colourless crystals are common, but large ones are quite uncommon. Highly saturated light blue crystals are rare.
2- Berbes mining area. Blue, violet and purple fluorite crystals, being the last probably the rarest, although pure blue is not common either. As a general and easy rule I could say that the closer to the red spectrum the rarer it is. Berbes area tends to the red spectrum (purple) much more than La Collada.
Zoned fluorite crystals in Berbes are common, but to find two different colours in the same crystal is unusual. Let me explain: You can find light purple crystals with a medium or dark purple phantom. The same stands for violet or blue. But to find a blue crystal with a purple or violet phantom is uncommon.
3- La Moscona Mine. Almost all fluorites from this underground mine are yellow. Ranging from pale and greyish yellow to honey coloured or extremely vivid yellow, being probably this last one the rarest among the yellows. Rarely, you can also find dark blue (with more or less violet – purple component)) and strong red.
Usually zoned fluorite crystals in La Moscona Mine show different shades of yellow – honey colour. Much more rare are specimens showing reddish phantoms, being the rarest the blue – yellow phantoms.
Note: Villabona Mine is a different fluorspar mine near Moscona Mine. Based on the specimens I would say that both mines operate the same fluorspar deposit. There are only around five kilometres between the entrance of the two mines. Specimens from these two localities are very difficult to distinguish. We could say that fluorite crystals from La Moscona Mine usually tend to warmer yellows (honey, reddish), whereas Villabona tend to cooler yellows (very light hints of green).
As I mentioned before, to differentiate fluorite specimens from La Moscona and Villabona is a very difficult task, even for experts! As a very personal note, I would say that is imposible to differenciate specimens from one and other locality as a whole! You can spot specimens from one and the other, based on famous pockets for example, but everyone will fail sooner or later.
4- Emilio Mine. The most common colour in this underground mine is the lack of colour! Usually greyish and sometimes gorgeous water clear fluorite crystals. Light blue is not uncommon, being dark blue quite uncommon, but not rare in some areas of the mine. As a general rule for this mine: colours are light.
Note: Jaimina Mine is a fluorspar underground mine very near Emilio Mine. Indeed one connects or almost connects with the other, although mine entrances are two kilometres away from each other. To distinguish between fluorite specimens from Jaimina and Emilio is practically impossible. The same “La Moscona – Villabona issue” here. Of course, you can distinguish pockets but not the specimens from either locality as a whole. As a very general and unprecise opinion, fluorite pockets in Jaimina tend to warmer blues, whereas Emilio tend to cooler blues. Could this be due to Jaimina being closer to Berbes than Emilio?
I hope you enjoyed this post. If you have any comments, ideas or suggestions please feel free to send me an email.
New photos will be added to this post in a near future. Stay tuned and sign up with us in our home page. www.spanishminerals.com
Juan Fernandez Buelga
Many of the fluorspar mines of Asturias are closed, being others active. Mineral collecting in them is forbidden by the mining companies which operate the mines and the Spanish law.
New Spanish Minerals update with 18 nice mineral specimens from different spanish localities. Mainly specimens from the northern areas of Spain but you will find a few mineral specimens from the south and central Spain. Enjoy!
Several localities of Asturias, Spain:
A few fluorites with barite or calcite from the famous Emilio Mine.
La Moscona Mine specimens. Including a rare dark blue one with blue and yellow phantoms in some of its crystals, etc.
La Viesca, La Collada dark blue and ligh blue specimens.
Fluorite specimens from Corta la Sirena, La Collada de Atras. Including one cabinet size specimen featuring the uncommon green coloured crystals.
A limonite ps. of goethite from Trinidad Mine, Malaga.