30 P. T. CLEVE, 



stratum of gray limestone. Epidote also occurs in the granite of Beef-Island (near Tor- 

 tola) and in quartz-veins on Culebra and S:t Thomas etc. 



32. Garnet is found in handsome crystals in Puerto Rico (at Rio blaneo in dode- 

 cahedrons of greenish or brown colour). Brown crystals of this mineral are found in the 

 diorite of Brown's Bay in S:t John. In the limestone at the westend of Tortola there 

 are numerous granules of garnet, and in the stratified rocks of Mary's Point (S:t John) 

 and of the smaller Virgin Islands (Coopers Island, Ginger Island etc), it is an important 

 ingrédient. Garnet (black and greenish) is found also, in the stratified silicious limestone 

 of S:t Martin. 



33. Mica. Dark mica in small leaves enters into the composition of the diorite of 

 the Virgin Islands, and occurs also in the granite and pegmatite of these islands. 



34. Desmine occurs in small, transparent crystals in fissures in the diorite at Brown s 

 Bay (S:t John), and also in fissures in metamorphic, stratified rocks at. Marys Point (S:t 

 John), accompanied by calcarious spar. It is found also in crystals near Brandwyn Bay 

 (Tortola). 



According to an analysis by Mr Th. Fiebelkorn the desmine from Mary's Point is 

 composed of: 



Si 56,02; Al 17,23; Ca 5,68; Na 2,15; H (before 100°) 2,36 H (by ignition) 17,06. 

 Sum, 100,50. 



Ratio of oxygen in R : R : Si : H. . 1:3,8:13,7:7. 



35. Laumontite is found on S:t Bartholomeiu , (near S:t Johns), in fissures of conglome- 

 rates in whitish, opake, crystals. It occurs also, in Anguilla together with calcarious spar 

 and Thomsonite in a kind of black amygdaloid rock. 



Analysis 1. of Laumontite from S:t Bartholomew sp. gr. 2,28, by Dr Th. Nordström. 

 2. Laumontite from Anguilla, by Mr L. J. Westman. 



Si Al Ca Na K H (before 100) H (ignition) Fe Ca C Sum. 



1. 53,67 20,44 9,79 0,59 1,25 2,20 » 11,32 » 0,59 99,75. 



2. 47,60 17,95 8,77 1,39 2,82 2,20 » 11,33 » — 7,72 99, /8. 



36. Prehnite occurs in small whitish, radiating, masses in the pegmatite-granite of 

 Beef-Island (Tortola) sp. gr. 2,98. 



Analysis (of mineral dried at 100°) by P. T. Cleve. 



Si 44,06; Al 22,94; Fe 1,98; Ca 26,62; H 4,44; Sum. 100,04. 



37. Thomsonite is found in black amygdaloid near Sandy Bay on Anguilla. It forms 

 whitish, radiating nodules. 



Analysis by Mr Nordström. 



Si 38,20; Al 31,29; Ca 12,33; Na 3,59; H (before 100°) 0,83; Loss by ignition 12,86; 

 Sum. 99,10. 



38. Calcarious spar is very common in the north-eastern islands. Fine crystals are 

 found in the fissures of gray limestone in S:t Bartholomew. Large crystaline and trans- 

 parent masses in Anguilla. In S:t Eustatius I have found fibrous lime in fissures of 

 trachyte. 



