lamprophyre [ altered greenstone ]: sphene, epidote and zoisite abundant and all embedded in a matrix of brown mica. A little hornblende is present. Apparently a thermometamorphosed greenstone, very highly altered. - see Lamplugh p309
Locality details
cliff S side of Barony Hill: altered greenstone dyke 0.5" from contact with 15' elvan (see p130 fig 36)