81 



. TAB. CCCXLV. 



CALX carbonata; var* fibrosa^ 

 Fibrous Carbonate of Lime. 



Div. 1 Imitative. 



JLhis substance has been long known ; but, 1 believe, has 

 not been noticed in any publication, if we except Dr. Kidd's 

 Outlines of Mineralogy ^ I have a piece in my possession 

 which is reported to have belonged to Da Costa, who was 

 said to be at a loss what to call it. I have also received it 

 from different friends at various periods j which shows it to 

 be sufficiently remarkable to attract notice, and that it 

 would appear a desideratum if passed over in this Work. 

 It was probably first noticed at Bath, or in the quarries in 

 that neighbourhood ; but is also found in most Limestone 

 quarries, varying much, accordingly as the stratum in which 

 it is found is more or less compact. I gathered the upper 

 specimen at Shotover Hill, where it is not uncommon |, 

 but these were rather remarkable, as the fibres were mostly 

 so very loose as to resemble in texture some rotten wood 5 

 which has lost the transverse fibres, and become petrified. 

 It separates into extremely fine filaments, which^ after se- 

 parating, break so nearly, if not quite, transversely^ as not 

 to show in the least the rhomboidal fracture (a character 

 peculiar to it and the Satin Spar)„ The middle figure shows, 

 the varieties of its colour, from nearly white to the 

 usual brown; and was sent from near Bath. The 

 lower figure is taken from a specimen found at Mit- 

 ford, with which I was favoured by Thomas Meade, Esq. * 



* I beg to correct a mistake in this gentleman's name ; — it should always 

 be read as above, not Charles, and should have the terminal e, 

 TOL. IV. M 



