["< sod > h the'''royal blue mountain quarry'''( first article introduced in'' [ [ blue mountain mystery ] ]'' ) is a large slate quarry, located on one of half the narrow gauge lines of the skarloey railway. < eod > < sod > the'''blue mountain coal quarry'''( first introduced in'' [ [ blue mountain mystery ] ]'' ) is a large slate quarry, located on one of the narrow single gauge spur lines of the skarloey railway. it is sometimes also served by a standard gauge branch line that breaches of the former peel godred line. < en eod >"]