282 Analysis of some Scottish Zeolites. 



with the experimental results as the formula I have given 

 above. As far as the Royal Island mineral is concerned, 

 however, the concordance is anything but satisfactory, 

 the quantity of silicic acid being much in excess of that 

 contained in either the Monte Baldo or Skye mineral. It 

 appears to me that there can be little doubt that the mineral 

 I analysed is actually pectolite ; at the same time I should 

 not wish to express too decided an opinion on the subject, as 

 a late experimenter (Frankenheim) has stated that pectolite 

 is an anhydrous mineral, and that the proportion of water 

 varies in different specimens, and consequently, in his opinion, 

 hygrometric. However this may be, the Skye mineral is cer- 

 tainly an hydrated one, according to my analysis, and several 

 determinations always shewed the same amount of water. 



The discovery of this mineral in Skye forms an interesting 

 addition to the mineral species of Scotland, where it has not 

 before been observed.* 



Scolezite.— The next is a mineral which is found in the 

 Island of Mull. It occurs in long radiated needles, of great 

 beauty and high lustre, contained in greenstone or trap- 

 rock, with crystals of epidote disseminated through it. 



It presents the characteristic properties of a zeolite, curl- 

 ing up before the blowpipe into a vermicular shape. It is 

 completely soluble in hydrochloric acid, and is partially so in 

 a solution of oxalic acid, oxalate of lime being precipitated. 

 Its external and chemical characters correspond with those 

 of scolezite, and its quantitative analysis generally agreeing 

 with those of that mineral, as obtained byFuchs and Gehlen : — 

 Silicic acid, 46*214 ; alumina, 27 00 ; lime, 13-450 ; water, 

 13.7g0_ 100444 



There is a slight excess of alumina, but, with this excep- 

 tion, the analysis accords with the formula of scolezite — 



Ca O Si 3 + Al 2 3 , Si 3 + 3 HO, 



its calculated constitution being as follows : — 







* This species occurs, although rarely, in cavities of trap-rocks, on the banks 

 of the Clyde. — Edit., N. P. Journal. 



