Pronunciation: [ˈamɪɡdjˌuːl] (IPA) 
The word "amygdule" refers to a small cavity or vesicle in volcanic rock. Its spelling follows the Latin root word "amygdala", which means almond, hence the "-ygd-" spelling. The "u" in "amygdule" is used to indicate the sound "yoo" as in "few" or "cue". In IPA phonetic transcription, the word is spelled əˈmɪɡdjuːl, with the schwa vowel sound /ə/ at the beginning and the long "oo" vowel sound /uː/ at the end.
Amygdule is a specialized geological term referring to a small, cavity-like structure found in certain volcanic rocks. These distinctive formations develop when gas bubbles are trapped within molten lava during volcanic eruptions. As the lava cools and solidifies, the trapped gases crystallize within the voids, forming distinct mineral deposits. The resulting amygdules are typically spherical or almond-shaped, ranging in size from a few millimeters to several centimeters in diameter.
Amygdules commonly consist of minerals such as quartz, calcite, zeolites, or agates, which grow within the gas bubbles and fill the empty spaces. This mineral-filled structure stands in contrast to the surrounding volcanic rock and often exhibits a contrasting color or texture, making it easily distinguishable upon close inspection.
These formations are of significant interest to geologists as they provide valuable insights into the conditions prevalent during the formation of volcanic rocks. The composition and size of amygdules can indicate specific geological processes that occurred while the magma was still below the Earth's surface. Additionally, they can assist in reconstructing the history of volcanic activity in a particular area.
Etymologically, the term "amygdule" stems from the Latin word "amygdala," meaning almond, due to the almond-like shape frequently observed in these geological structures. Amygdules are found in volcanic regions across the globe, contributing to our understanding of Earth's geological history and the processes that shape its surface.
The word "amygdule" has its origins in the Latin term "amygdala", which means "almond" due to its shape. It comes from the Greek word "amygdale", which also means "almond". In geological contexts, "amygdule" refers to a small, almond-shaped cavity in igneous rock that is often filled with minerals such as zeolites or quartz.
