Proceedings of the United States National Museum . Fig. 29.—Apophyllite showing com-bination OF PYRAMID WITH FACESOF FOUR PRISMS. Albite. Chlorite. Hornblende (asbestiform) Epidote (hour-glass). Axinite. Quartz. Prehnite. 8. Datohte. 9. Chabazite. 10. Stilbite. 11. Laumontite. 12. Opal (hyalite). 13. Apophyllite. 14. Calcite. The position of albite is rather definitely fixed by its occurrenceunderlymg both chlorite and hornblende. Chlorite is in most cases a very early mineral although it may alsooccur as a later deposit. 94110—24- 82 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. The asbestifo
Proceedings of the United States National Museum . Fig. 29.—Apophyllite showing com-bination OF PYRAMID WITH FACESOF FOUR PRISMS. Albite. Chlorite. Hornblende (asbestiform) Epidote (hour-glass). Axinite. Quartz. Prehnite. 8. Datohte. 9. Chabazite. 10. Stilbite. 11. Laumontite. 12. Opal (hyalite). 13. Apophyllite. 14. Calcite. The position of albite is rather definitely fixed by its occurrenceunderlymg both chlorite and hornblende. Chlorite is in most cases a very early mineral although it may alsooccur as a later deposit. 94110—24- 82 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. The asbestiform hornblende definitely underlies laumontite andstilbite in one specimen, but on another, fibers seem to penetratealbite crystals, and in still another it appeared to rest upon of hornblende of this type were also seen inclosed in albite ina thin section of the albitic pegmatite and it may precede albite information or, more probably, its deposition extended over a consid-erable range. Epidote of the hour-glass type was seen imbedded in chlorite inasbestiform hornblende, and in prehnite, so that it is apparently con-temporaneous with all of these. Prismaticcrystals associated with the axinite are aboutcontemporaneous with the latter and theaccompanying hornblende. Axinite was found in circumstances whichindicate it to be later than diopside, con-temporaneous with hornblende and epi-dote and earlier than apophyllite. Quartz was seen in only one specimenwhere it was later than chlorite and dis-tinctly earlier than datolite. Prehnite is apparently about cont
Size: 1578px × 1584px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
