TRANSACTIONS. 



Notes on some Rare Minerals occxtrring in the Dis- 

 trict. By Patrick Dudgeon, Esq. of Cargen. 



The granite or rather syenite of this locality — including the 

 districts of Criffel and Dalbeattie — is remarkable in having 

 diflfused through it in more or less abundance crystals of 

 sphene (a silicate of lime and oxide of titanium). Sphene is 

 not a common mineral in Great Britain, and is found in few 

 localities, generally in small crystals disposed through gneiss 

 and syenite. In this district the crystals are generally small, 

 the largest I have met with not being over -^ of an inch 

 across ; colour hair brown, lustre adamantine. The crystals 

 are generally sparingly distributed through the syenite, but 

 I have met with it in patches in such quantities as almost 

 to form a constituent of the rock. Some books on mineral- 

 ogy mention zircon as being found in the syenite of the dis- 

 trict. I think this is a mistake. The late Mr Copland of 

 Blackwood, who carefully surveyed the district, could never 

 find any crystals of this mineral, and I also have looked for it 

 in vain. The error — if it is one — has probably arisen from 

 the peculiar form of some of the crystals of sphene, which, 

 examined superficially, have much the appearance of zircon 

 crystals. 



Professor Heddle and I also found in blocks of syenite 

 about a mile up the Newabbey Burn small crystals of allan- 

 ite, a mineral containing the rare metal cerium : this is the 

 fir.st time this mineral has been found in Great Britain. In 

 the same locality we found small granular masses about the 

 size of a pea of a black vitreous mineral supposed to be 

 gadolonite. The crystals of allanite though small were quite 



