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Amphibole

/ˈæmfɪboʊl/noun

A large group of dark, double-chain silicate minerals including hornblende, common in igneous and metamorphic rocks.

The Greek roots

ἀμφί
amphí
on both sides
+
βάλλω
bállō
to throw

Literally: thrown both ways

The story of the word

René Just Haüy named the group in 1801 using the Greek word for ambiguous, because these minerals are so easily mistaken for others, and he wanted the name to warn geologists. The same adjective gives amphiboly in logic, a fallacy where a sentence can be pulled two ways by its grammar. Some amphiboles crystallise as fibres, which is how one of them, crocidolite, became blue asbestos.

How it travelled
Ancient Greek → French coinage → English
First recorded
19th century

Same family

amphitheatreamphibianballisticproblem

In a sentence

Black needles of amphibole stand out against the pale feldspar.

Built on the same root

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