494: Heivett and Shannon — Orientite, a neiv 



fill cracks that cut across plumose inanganite and are 

 clearly later than that mineral. 



In some places manganite forms plumose aggregates 



Fig. 1. — Black, manganese oxide (psilomelane ?) ; gray, crystals (o), 

 orientite; white (c), calcite. X 25 diameters. 



Oxides form nuclei in orientite; druses are filled "with calcite. Mottled 

 appearance of orientite is due to its high index of refraction. 



Open cut. jSTo. 20, Costa Claim, 6 miles south of Bueycito, Oriente, Cuba. 



that have associations similar to psilomelane and is there- 

 fore probably contemporaneous with it. It also forms 

 short wedge-shaped prisms 1 to 2 mm. long, which occur 



Fig. 2. — Black, plumose aggregates of manganite (?); gray (o), orien- 

 tite; white (op), opal ( f ) ; white (s), open space. X 6 diameters. 



Veinlets of orientite cut and are later than the aggregates of manganite. 

 Open cut No. 8, Costa Claim., 6 miles south of Bueycito, Oriente, Cuba. 



