WONDER-EARTH. • 

 The ciystals, of a pale yellow colour, and 

 nearly transparent, were disposed on vesi- 



Fig. 467. 



ciilar iron-ore. It has also been found in 

 Cornwall (^fig. 467). 



Brit. Mus., Case 52. 



Wonder-earth. See Teratolite. 



WOOD-ARSENIATE OF CoPPER. A fibrOUS 



kind of Olivenite, found investing? or pass- 

 ing into the crystallized variety. It is found 

 in Cornwall, at Huel Gorland, Huel Unity, 

 Carharrack, Gunnis Lake, and amianthiform 

 at Tin-Croft. 

 31. P. G. Principal Floor, Wall-case 2. 

 Wood Coal, Bakewell. See Cannel 

 Coal. 



The name is, also, sometimes given to 

 fibrous Lignite. 



Wood Iron-ore. A variety of Limonite 

 with a fibrous structure, found at the Royal 

 Restormel Iron Mines, Lostwithiel, in Corn- 

 wall. 



M. P, G. Principal Floor, Wall-case 49, 

 Nos. 337, 338, and 354. 



Wood-Opal ; Woodstone, Jameson, Kir- 

 wan. A variety of Opal, with a peculiar 

 ligneous structure. It is somewhat harder 

 than Semi-Opal, from which it does not 

 materially differ in fracture, translucency. 

 and lustre. It is found forming large trees 

 in the pumiceous conglomerates of Saiba, 

 near Neusohl and Kremnitz, in Hungary ; 

 in Faroe ; near Hobart Town, in Tasmania, 

 &c. 



Portions of the silicified stems of coni- 

 ferous trees which are met with lying pro- 

 strate in the dirt-beds, near the base of the 

 Purbeck strata of Dorsetshire, are some- 

 times partially converted into this sub- 

 stance. 



The whole of tha Desert between Cairo 

 and Suez (for about 86 miles) is covered 

 with silicified trunks of trees, belonging, 

 without exception, to the Nicolia JEgyptiaca 

 ( Unger), sometimes 40 or 50 feet long, and 

 1 or 2 feet in diameter, and lying in all 

 directions. j 



'J'he fragments are losely imbedded in the > 

 sands of the Desert, and may be seen in their ! 

 original situation, in Tertiary sandstone, at 

 the Gebel Akmar, a locality strikingly 

 analogous to the sandstone containing wood- 

 stems near Gleischenberg, in Styria. Prof. I 



WORTHITE. 411 



Unger is of opinion that the trees became 

 silicified in consequence of their having 

 drifted into a basin separated from the main 

 sea, and filled with water saturated with 

 silica. 



There is another deposit of fossil wood 

 near Assuan (Syene), on the frontiers of 

 ^gj'pt and Nubia ; and a third near Koum- 

 Ombos, in the Desert M'est of the Nile. 



The wood of these two latter localities be- 

 longs to an undescribed coniferous tree, of 

 the Araucarian division, for which the name 

 of Dadoxylon JEgyptiacum has been pro- 

 posed by Prof. Unger. 



In the Island of Unga, on the north coast 

 of America, there are blocks of wood and 

 whole trunks of trees, (some of which dis- 

 tinctly show the marks of hatchets), con- 

 verted into Opal. 



Wood Opal is made into snuff-boxes and 

 other ornamental articles, at Vienna, &c. 

 Brit. Mus., Case 24. 



31. P. G. A 47, in Hall, from the Desert, 

 near Cairo. Lower Gallery, west side, on 

 floor near the stairs. Horse-shoe Case, No. 

 759. 



Wood-tin, or fibrous oxide of tin, is a 

 variety of Cassiterite, containing from 5 to 

 9 per cent, of oxide of iron, met with in 

 a few mines and some of the principal stream 

 works in Cornwall, frequentl}' in masses of 

 several pounds weight. 



It occurs in reniform, globular, or in broken 

 ■wedge-shaped pieces, the surfaces of which 

 generally present a water-worn appearance. 

 The structure is concentric-lamellar in one 

 direction, and divergingly fibrous in the 

 other, which, in connection with its brown 

 and yellow colour, causes it to present a 

 ligniform appearance. 



Localities. Cornwall • Carnon Stream, Bod- 

 min Moor, St, Austell, Roach, Pentuan, 

 Polberrow C(msols, Sancreed, and elsewhere. 

 Brit. Mus., Case 18. 



31. P. G. Principal Floor, Wall-case 8, 

 Nos. 406 and 407 (British). 



WoRTHiTE, Phillips. A silicate of alu- 

 mina, found in transparent and foliated, 

 colourless crystalline masses in Sweden or 

 Fiiiland. It has a vitreous lustre, scratches 

 Quartz, and, according to Hess, is compo- 

 sed of alumina 54'45, silica 40*79, water 

 4-76 = 100. H. 7-25. S.G. 3. 



BB infusible. 

 ■ Name. After the discoverer, Fr. Von 

 Vs^orth, secretary to the Mmeralogical 

 Society of St. Petersburgh. 

 Brit. Mus., Case 26. 

 Worthite has been proved by the recent 



