... and some mineral-encrusted buildings

People have used blocks of broken, cut or polished stone for building and decoration since the dawn of human time. However, it's less common to use individual crystals in buildings.

Thw "Morrua Hilton" is a very fancy 1960s (?) house at the Morrua lithium-tantalum pegmatite in Mozambique. It was built by the brutal Portugese colonial administration in something of a James Bond villain style, with a huge swimming pool, folly castles, and modernist main building. Mineralogically the main building is remarkable, in being clad in large plates of lilac "lepidolite" lithium mica:

Large plates of lepidolite in the walls of the Morrua Hilton

The mine was the scene of fighting in the civil war which was fomented by South Africa and Rhodesia following Mozambique's independence in 1975, but the building has survived. When I visited, the mine was under redevelopment by Noventa. It was also the home of a large garimpeiro community of artisanal tanatalum miners, who extracted tantalum minerals from mine waste, and the local river with extraordinary skill. Noventa has good relations with this community, and is happy to work alongside them.


Another odd mineral-encrusted building can be seen at the Sorbas gypsum caves, in Andalusia, SE Spain. Here, modern buildings beside the visitor centre are harled with glittering blocks of coarse selenite gypsum:

Coarse selenite gypsum bocks coating walls at the Sorbas caves visitor centre

The gypsum deposits of the Sorbas Basin were formed by evaporation of a repeatedly-replenished marginal basin during refilling of the Mediterranean following the great Messinian event when the whole sea dried up. Unlike the fine-grained sabkha gypsum typical of the Permian in the UK, the Sorbas gypsum formed as a mush of large clear selenite crystals on the seafloor - very spectacular rocks.

Lepidolite and gypsum - any offers of other minerals which have been used to coat buildings?

Lovely rocks in airports...

In January 2013 Volcanoclast's blog asked readers for nice examples of polished rocks in tabletops, and similar decorative settings. I'm a year too late to win any prizes, but this reminded me of some nice rocks I saw in 2011, flying to Mozambique to look at tantalum pegmatites.

First, Dubai. As you might imagine, a very classy airport indeed. The polished stone floors include a lot of beautiful blue sodalite syenite:

I'm not quite sure where this nice rock comes from: there seem to be quite a lot of commercial sources  e.g. Zambia, the Andes, Namibia,  Brazil and other places. The abundance of green aegirine(?) in the Dubai floors seems rather like the Azul Bahia rock from the Proterozoic Southern Bahia Province, in Brazil.


Unlike many sodalite syenites, the Dubai floor rock shows very nice preservation of original igneous textures. While much blue sodalite in syenites is probably  the result of post-magmatic replacement, it can also form as a primary magmatic product.

 

Might this be magmatic sodalite in these Dubai floor slabs?

And so on to Oliver Tambo airport, Johannesburg. Again, a lot of very nice polished  natural stone used in the airport. I was particularly impressed by these sabs, showing lovely pegmatitic veins and pods in granite:

Some of the feldspars in these pegmatites even showed traces of moonstone "schiller" effect .The host granite is heterogeneous, and almost banded, maybe suggesting a rather dynamic environment, but the late pegmatite pods have clearly crystallized in situ in very still conditions. Can anybody suggest the source of these beautiful rocks?