CAKIXG COAL. 



TheCairagorm is frequently manufactured 

 into jewelry, and is the stone gerei-ally used 

 for ornamenting the handles of dirks, pow- 

 der-horns, snuff-mulls, and other articles of 

 a similar kind which form part of the High- 

 land costume. (See Smoky Quartz.) 



Brit. Mus., Case 20. 



M.P. G. Horse-shoe Case, No. 507. 



Caking Coal. The name given to those 

 kinds of bituminous coals which bum 

 readily with a yellow flame and have a ten- 

 dency to cake, or to run together, in the 

 lire. The Newcastle coals are of this de- 

 scription. 



Calamine, Dana. See Smithsonite. 



Calamine, Jameson, NicoJ. Hexagonal. 

 It is found in obtuse rhomboliedrons, and 

 in long quadrilateral tables, which are some- 

 times modified ; also compact, mammillated, 

 fibrous, and incrusting other minerals, and 

 occasionally earthy and friable. Colour 

 greyish-white, or yellowish -grey, some- 

 times inclining to various shades of green 

 and brown. Lustre vitreous, inclining to 

 pearly. Translucent or opaque. Streak 

 white. Yields easily to the knife. Brittle. 

 Fracture uneven. H. 5. S.G. 4 to 4-5. 



Fig. 70. 



Camp. Zn C = carbonic acid o5'19, oxide 

 of zinc 64-81=: 100, but frequently contain- 

 ing carbonates of iron, manganese, or lime. 



^5 flies to pieces and becomes white, but 

 is infusible either alone or with borax. 

 Dissolves with effervescence in nitric acid. 



Localities. — English. Huel Mary, Corn- 

 wall; botryoidal at Roughten Gill, in Cum- 

 berland; mammillated and in crusts at 

 Alston Moor; radiated, of a bluish-green 

 colour, near Matlock, in Derbyshire; the 

 Mendip Hills, in Somersetshire, sometimes 

 in large pseudomorphous crystals after Cal- 

 cite; crystallized in obtuse"^ rhombohedrons 

 near Holywell, in Flintshire. — Scotch. Lead- 

 hills. — Irish. Donegal and Galway. — 

 foreign. A dark brown variety, containing 

 Cadmium, and another of a beautiful bright 

 green, are found at iS'ertschinsk, in Siberia. 

 Other localities are Dognatzka, in the Ban- 

 nat of Temeswar, in Hungary ; Raibel and 

 Bleiberg, in Carinthia ; Tarnowitz, in Si- 

 lesia ; Altenberg, near Aix-la-Chapelle ; 

 near Santander in Spain ; &c. 



Name. The name is derived from cala- 

 mus, a reedj because during the process of 



CALCAREOUS TUFA. 



59 



smelting it adheres to the bottom of the 

 furnace in the form of reeds. 



This ore of Zinc is the Smithsonite of 

 Haidinger and Von Kobell. It does not 

 occur crystallized so often as the silicious 

 oxide (see Smithsonite), being more fre- 

 quently stalactitic, reniform, mammillated, 

 cellular, and amorphous, and frequently as- 

 suming the aspect of Chalcedony. 



Brit. Mus., Case 49. 



3I.F G. A 33 in Hall ; large cube, from 

 the Vieille Montague Mines. Principal 

 floor, Wall-cases 12 and 33 (British), 21 

 (Foreign). 



Calamite (from calamus, a reed), A soft, 

 asparagus-green, translucent variety of Tre- 

 molite, from Normarken, in Sweden, where 

 it occurs in longitudinally striated rhombic 

 prisms imbedded in Serpentine. 



Calc Tuff, Jameson. See Calcareous 

 Tufa. 



Calcareous Epidote. See Zoisite. 



Calcareous Iron-Ore, Kinvan. See 

 Chalybite. 



Calcareous Mesotype. See Scole- 



ZITE. 



Calcareous Ophiolite. The name pro- 

 posed by T. Sterry Hunt for the varieties 

 of Serpentine containing intimate admix- 

 tures of Calcite. 



Calcareous Spar. See Calcite. 



Calcareous Tufa, A loose and friable 

 variety of carbonate of lime, deposited in 

 and about waters which are charged with 

 lime. These sometimes form extensive beds, 

 and are well adapted for building purposes, 

 from their softness when first quarried and 

 the hardness they subsequently acquire on 

 exposure to the atmosphere. Some of the 

 beds at the base of the Pur.beck formation 

 appear to have been formed after the man- 

 ner of Tufas, and the tertiary fluvio-marine 

 Limestones of the Isle of Wight also afford 

 other examples of Calcareous Tufas, having 

 evidently been deposited at the bottom of 

 lakes impregnated with lime, or, in some 

 cases, subaerially. Calcareous Tufa is fre- 

 quently formed on the leaves and stems of 

 plants, which are then said to be petrified or 

 converted into stone, and the waters which 

 possess this property are called petrifying 

 springs. At Matlock there are springs of 

 this description, where objects speedily be- 

 come incrusted with carbonate of lime ; but 

 in Italy there are very extensive deposits of 

 Calcareous Tufa, as at Terni, and on the 

 banks of the river Anio, near Tivoli. (See 

 Travertine.) The temples of PjEstum are 

 built of Tufa, which has become hardened 

 by time and exposure; to which circum- 



