Lectionary Calendar
Friday, November 22nd, 2024
the Week of Proper 28 / Ordinary 33
Attention!
StudyLight.org has pledged to help build churches in Uganda. Help us with that pledge and support pastors in the heart of Africa.
Click here to join the effort!

Bible Encyclopedias
Aphanite

1911 Encyclopedia Britannica

Search for…
or
A B C D E F G H I J K L M N O P Q R S T U V W Y Z
Prev Entry
Apex
Next Entry
Aphasia
Resource Toolbox
Additional Links

a name given (from the Gr. acf)av is, invisible) to certain dark-coloured igneous rocks which are so fine-grained that their component minerals are not detected by the unaided eye. They consist essentially of plagioclase felspar, with hornblende or augite, and may contain also biotite, quartz and a limited amount of orthoclase. Although a few authorities still recognize the aphanites as a distinct class, most systematic petrologists, at the present time, have discarded it, and regard these rocks as merely structural facies of other species. Those which contain hornblende are uniform, fine-grained diorites, vogesites, &c., while when pyroxene predominates they are ascribed to the dolerites, quartz-dolerites, &c. Hence, any rock which is compact, crystalline and fine grained, is frequently said to be aphanitic, without implying exactly to which of the principal rock groups it really belongs.

Bibliography Information
Chisholm, Hugh, General Editor. Entry for 'Aphanite'. 1911 Encyclopedia Britanica. https://www.studylight.org/​encyclopedias/​eng/​bri/​a/aphanite.html. 1910.
 
adsfree-icon
Ads FreeProfile