( 61 ) 



The greater part of the torarnalli of gemmers belongs properly to 

 zircon. 



Serendihite. — A borosilicate of alumina and lime with magnesia 

 and alkalis. Found only in Ceylon. In small crystals in diopside 

 rock at the junction of limestone and granulite. Dumbara district, 

 Central Province. 



Scapolitey Ca^AleSieOosNa^AlgSigOj^Cl.— Abundant in the 

 vvollastonite-scapolite gneisses of Guile ; common in limestone- 

 granulite junction rocks. Sometimes an accessory mineral in 

 limestones. 



Stilbite, (Na2Ca)Al2Si60i66H20. — In minute crj^stals ; from 

 Nilhene, near Baddegama, Southern Province. 



iJomfe, Ca2Alo(A10H)(SiO J3. 



AUanite, (CiFe)2(AlGeFe)o(A10H)(SiO J3.— In coarse granitic 

 dykes near Balangoda. 



Beryl, Be3Alo(Si03)c. — The pale varieties of emerald known as 

 aquamarine are abundant in gem gravels. Ceylon specimens with 

 the true emerald colour have been very rarely met with. 



Gordiei-ite (lollte), (MgFe)4Al4Si50i §. — In rolled crystals known 

 as water sapphire. Many stones, however, known as water 

 sapphire belong to topaz, and are colourless. 



Garnets. — Several types of garnet occur in Ceylon. Amongst 

 these are probably — 



Ginnamon stone, Ca3Al 0(8104)3. — Not known in situ. 



Pi/ro/je, MggAl 0(8104) 3. X These include the red and pink- 



Almandite, Fog Al2(8i04)3. I ish-red garnets so common in and 



Spessartite, Mn3Alo(Si04)3. ) characteristic of the granulites. 



/^ 



Fig. 6. — Zircon. 

 Zircon, ZrSi04. — A very abundant mineral in Ceylon ; occurs 

 in the granulites ap a microscopic constituent; near Ralanproda 



