Note 6 — Chapter VI

Of local specimens we were shown varieties of the Mó-berg (Palagonite tuff), especially from the Seljadalr, which feels soft, between chalk and steatite, some white or dull yellow, acted upon by acids; others brown and black. Palagonite conglomerate with large pieces of felspar. Blue compact basalt from Kjallarnes, with and without drusic cavities; hexagonal basalt; reniform pebbles of the same material. Jaspers, red, yellow, and green, from the north, the latter containing copper. Dolerite or greenstone. A collection of Hekla lavas, passing from the porous to the highly compact. Micaceous “glimmer schiefer” studded with garnets. Zeolite and Iceland spar; silicates of lime. Quartz needles from the Geysir, and other quartzes, uncrystallised and crystallised into fine hexagons, large and small, often contained in bolides. Aluminous clays and oxide of iron, some with regular angles and metallic revetments. Concretions from Laugarnes and the Geysir, the stalks of plants resembling petrified bones. The Cyprina Gaimardi and Byssomea arctica from the north. Other shells: Balanus, Mya truncata, Venus Islandica, Lepas, Bulla, and Turbinus. True cannel coal from Suderoe, to the west; lignites, old and new; pieces of Surtar-brand, flat, and showing impressions of leaves; large fragments of true pitch-stone resembling, and others in transition to, obsidian. Hrafntinna (Raven-flint, Gagates Islandicus), obsidian or Iceland agate, black and liver-brown, like Jews’ pitch or asphalt, from Mý-vatn and the Hrafnatinnuhraun of Hekla. Henderson (i. 178) mistranslates Hrafnutinna, “Piedra de Galinazzo, or raven-stone” (for buzzard-stone). Agates, chalcedonies, and transitional opals, from Múla Sýsla, Tindastoll, and Heimaklettur, in the Vestmannaeyjar: according to Professor Abel, the south-eastern coast affords the noble stone, and the islanders believe that about 1821 a Mr Methley (?) carried home a valuable collection. Professor Árnason kindly gave me a little box of chalcedonies which looked like onyxes.