An intrusive rock, similar to dolerite but with an excess of quartz. Dolerite is similar in composition to basalt, which is eruptive (from volcanoes), and gabbro, which is plutonic. The differing crystal sizes are due to the different rate of cooling, basalt cools quickly and has a very fine structure, while gabbroDolerite is intermediate. cools very slowly, at great depth, and large crystals develop. Quartz-dolerite is very common in central Scotland, in intrusive formations, sills and dykes, and is widely quarried for roadstone. It was used with some success for making millstones at one time, the Millstone Grit part of the Carboniferous strata not being present in Scotland, but it is no longer used for this purpose, and would probably be illegal now due to the formation of small quartz and other silicate particles, which could cause the serious respiratory disease silicosis. In Scotland quartz-dolerite is commonly known as whin or whinstone. Quartz-dolerite contains many cooling fractures and weathers badly, becoming unstable. It is not uncommon for large boulders to break loose, and significant rockfalls are not uncommon. It is regarded as dangerous as far as climbing is concerned. It is widely accepted to have complete and proper safety attire when dealing with this rare stone.
Cherry blossoms
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On the Vernal Equinox I walked in Green-Wood Cemetery under a high, racing
sky and patchy cloud. In an early-blooming cherry, some house finches were
v...
Derbies spice up 2020 Absa Cup draw
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The 2020 Absa Cup quarter-final and semi-final draw was held on Tuesday, 10
March at the Southern Sun Hotel in Lusaka. Hosted by FAZ Acting
Communications ...
Words are potent
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Words weather written or spoken carry power. Words determine destinies. The
quality of you words determine the quality of your life. God created the
whole
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