obsidian

noun

ob·​sid·​i·​an əb-ˈsi-dē-ən 

: a dark natural glass formed by the cooling of molten lava

Examples of obsidian in a Sentence

Recent Examples on the Web

HigherDOSE’s five-layer construction includes a charcoal layer to mitigate EMF and ELF, a clay layer that emits negative ions, a medical-grade magnetic strip and a healing crystal layer of amethyst and obsidian. — Samantha Agate, Kansas City Star, 21 Sep. 2026

Focusing on the Ararat-1 Cave site in the Armenian Highlands, Arik explained how nearly 1,800 stone artifacts (including local chert and obsidian transported over considerable distances) reveal a surprisingly sophisticated technological system. — Christopher McFadden, Interesting Engineering, 18 Sep. 2026

Humans have been using materials such as polished obsidian as mirrors for 8,000 years. — Literary Hub, 15 Sep. 2026

All the sites have the more common glossy black obsidian as well. — Bay Area News Group, Mercury News, 20 Aug. 2026

Word History

Etymology

earlier as adjective, "made of obsidian, resembling obsidian," borrowed from Latin obsidiānus, manuscript variant of obsiānus, from Obsius, traveler named by Pliny who found the stone in Ethiopia + -ānus -an entry 2

Note: The sole authority for the existence of the eponymous Obsius is Book 36 of the elder Pliny's Naturalis historia. Note that the Aethiopia of Pliny corresponded very roughly to the present-day states of Sudan and Ethiopia.

First Known Use

1794, in the meaning defined above

Rhymes for obsidian

• gideon
• lydian
• ascidian
• dravidian
• quotidian
• enchiridion

Kids Definition

obsidian

noun

ob·​sid·​i·​an əb-ˈsid-ē-ən 

: a dark natural glass formed by the cooling of lava