BULL. GFOL..SOC. AM. 



VOL. 16, 1904, PL. 28 



Figure I.— Transparent Calcite (X 6) 



Figure 2.— Calcite Spheruute (X 15) 



Figure 3. — Calcite Spheruute (X -0 



Figure +.— Collapsed Glass Cavity (X ^) 



Figure 5. -Cavity in coarse porphyriti 



Diabase (X 4) 



Figure 6.— Arrowhead Twin of Labradorite 



SPHERULITES IN GLASS 



