Geology Word of the Week: A is for Amygdale

amygdale, amygdaloidal, amygdule, Geology Word of the Week, lava, vesicle, vug, zeolite 1 Minutes
Amygdaloidal basalt collected during dredging along the Ninetyeast Ridge in the Indian Ocean in summer 2007.

def. Amygdale (also spelled Amygule):
Vesicles, generally in extrusive igneous rocks, that are filled with secondary minerals, most commonly quartz, calcite, chlorite, and zeolite.

When a rock contains amygdales, geologists often describe it as an amygdaloidal rock. For example, basalt is often described as amygdaloidal basalt.

Here are a few previous, related geology words of the week that may be of interest:

V is for Vesicle (and Vug)

Z is for Zeolite

M is for Magma

And here are a couple more pictures of amygdaloidal rocks:

Amygdaloidal basalt from the Isle of Skye, Scotland. Picture courtesy of Matt Kuchtam.
A zeolite amygdale in a rock collected from Quartzville, Oregon. Picture courtesy of Dana Hunter.

 

***Thanks to my twitter follower Laura Hamilton for suggesting this week’s word. Thanks to Matt Kuchtam, Dana Hunter, and Lockwood De Witt for providing pictures.***

Published by Evelyn Mervine

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3 thoughts on “Geology Word of the Week: A is for Amygdale”

  1. Just happened upon your website, love the Geology words of the week! I’ve just begun studying it in college and it’s great to learn more about topics we’re going over in class as well as some new ones. Keep up the good work! 😀

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  3. Hi – I’m the project coordinator for the MARGINS Mini-lesson project. We’ve designed open access lessons for undergraduate use from a decade of MARGINS NSF funded research. One of our authors is seeking permission to reuse the zeolite figure above as an illustration in her lesson. (A zeolite amygdale in a rock collected from Quartzville, Oregon. Picture courtesy of Dana Hunter.) Could you please help me get in touch with the authors?

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