284 I>. K. Emerson — Mineralogical Notes. 



have grown directly against the flat surface of a plate produc- 

 ing basal faces on the quartz which replace the pyramid 

 entirely and take a sharp cast of the striated crystal face of the 

 anhydrite. 



2. Paragenesis of minerals in diabase. 



A Quarry JS T o. 1, Westtield. 



1. Anhydrite in blades 2 inches long and 1 inch wide. 



2. Massive transparent calcite. 



3. Datolite massive and in one inch crystal. 



4. Solution of anhydrite. , 



5. Diabantite replacing anhydrite. 



6. Coarse wine-yellow dog-tooth spar. R 3 sometimes 



truncated at apex by R. 



7. White coating of chalcedony. 



8. Fine-grained white dog-tooth spar, R 6 , ocR. 



9. Change of diabantite to limonite. 



B Cheapside Quarry, Greenfield. 



1. Anhydrite in blades. 



2. Quartz. 



3. Solution of anhydrite. 



C 



1. Anhydrite. 



2. Datolite and calcite. 



3. Calcite. 



4. Solution of anhydrite. 



Amherst, Mass. 



