Dalnabo Quarry
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Condition (NatureScot)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| F1 | Mineralogy of Scotland | Favourable | — | 2010-04-30 |
Geology & landscape
Mining / Industrial: Quarry · Rock Type: Limestone
Description
DALNABO QUARRY This quarry in impure limestones, on the south side of Glen Gairn, has yielded some magnificent specimens of minerals which originated when silica-bearing impurities reacted with the calcium carbonate which makes up the bulk of the limestone when the rocks were buried deep within the Earth’s crust. The main minerals include diopside (calcium magnesium in silicate – CaMg(Si2O6), wollastonite (calcium silicate – CaSiO3), actinolite (a complex silicate of magnesium calcium and iron), grossularite (calcium aluminium silicate), idocrase (a complex silicate of calcium, magnesium and iron) and epidote (an alumino-silicate of calcium and iron). Other minerals present are pyrrhotite (iron sulphide – Fe7S8), sphene (calcium – titanium silicate), plagioclase feldspar (calcium alumino – silicate) and prehnite (a calcium hydroxy – alumino – silicate). Despite being disused for more than fifty years, the faces are still productive. The idocrase, of a dark sherry brown colour, is of particular interest and can be studied in the copious volumes of loose blocks piled against the faces.