Tag: calcite

england fossils geology palaeontology

Boxstones: In search of Miocene Suffolk

Tim Holt-Wilson (UK) The date is 24 May 2014 and I am browsing across East Lane Beach at Bawdsey in southeast Suffolk. A brown lump of sandstone with a white fossil shell impression catches my eye. A boxstone. This is the first one I have ever found with a fossil in it. Looking closely, I see that the sea has abraded the shell’s outlines, although the margins have survived better than the rest, so it should be possible to identify the specimen (Fig. 1). Fig. 1. Boxstone, found 24 May 2014. Boxstones are fragments of a vanished world. They are … Read More

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geology minerals north america volcanoes

Volancoes of Big Island, Hawaii (Part 1)

Dr Trevor Watts (UK) We (my wife Chris and I) enjoyed our fourth visit to Big Island Hawaii in May 2013 so much that we decided to return to the same places in October 2014. We were hoping to see similar events and activities, which we had found particularly interesting and accessible over the years. Every time we visit, something changes or isn’t possible, but this time was a little more changeable than most. The intervention of three ladies altered a few of our plans – Iselle, the hurricane that visited the southeast of Big Island two months before we … Read More

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europe historical / biographies minerals mining museums, societies urban, art, anthropology

Marble from the Isle of Paros in Ancient Greece: A tour of the ancient quarries

Dr Robert Sturm (Austria) This is the second of four articles on the quarries of the ancient world and later, and, in particular, the marble that was quarried there and the artwork that was made from it. The first was Mining in Ancient Greece and Rome. Some introductory words In general, marble represents a coarse-grained metamorphic rock primarily consisting of the minerals calcite (CaCO3) and dolomite ((Ca,Mg) (CO3)2). The word ‘marble’ may be derived from the Greek term ‘marmaros’ (μάρμαρος), which means ‘shiny stone’. The earliest use of the rock dates back to the fourth millenium BC, when it was … Read More

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minerals

Agate: A mineral that develops with age, water and moganite

Terry Moxon (UK) Agate is banded or variegated chalcedony and this distinctive appearance allows a ready identification from any source. Many agate thick sections from basic igneous hosts are reminiscent of a series of distorted onion-like rings with the initial bands closely replicating the shape of the supporting gas cavity. However, the banding is frequently distorted and this general pattern is known under various names, for example, fortification or wall lining. A second type is less common and demonstrates apparently gravity-controlled horizontal bands. Agate host rocks are varied but the most abundant agate sources are the gas cavities of basic … Read More

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minerals wales

Mineral classics from Wales

Tom Cotterell (UK) Ask any mineral collector to name a classic mineral locality or region in Britain and they will probably think of Cornwall or Devon, perhaps Weardale in Co Durham, or even the Caldbeck Fells or the West Cumbrian iron mining district in Cumbria – but probably not Wales. This is not to say that Wales has no classic minerals, but is perhaps a reflection of collecting habits and the preference for large, brightly coloured crystals. Wales has a long history of mining dating back to, at least, the Bronze Age, but, unlike some other regions, there does not … Read More

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minerals

Collecting fluorescent minerals

Clay Carkin (USA) Compared to the collection of fossils and traditional mineral specimens, the hobby of collecting fluorescent minerals is in its infancy. Even though Sir George Stokes discovered the property of fluorescence in the early 1800s (from the blue glow of fluorite in sunlight), it was not until the 1940s that portable ultraviolet (UV) lamps became available to the public. During WWII, the United States needed the metal tungsten, which is present in the mineral scheelite. Mr Thomas S Warren (president and founder of Ultra-Violet Products Inc.) invented a portable ultraviolet lamp to help prospectors locate deposits of this … Read More

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geology minerals

Collecting minerals around the world

 Trevor Devon (UK) At some time, I suppose we have all collected rocks or minerals when we were travelling to new places, mostly as mementos, but nothing quite beats the buzz of collecting specific minerals from classic locations with like-minded colleagues. This type of collecting implies you know something of the geology and mineralogy of the location, what sort of rock to explore (often with a sledgehammer to start with) and what colour and shape the minerals are likely to be found in. Of course, it helps to travel with colleagues who have been there before and can show you … Read More

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