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AGAMS Monthly Geology News – September 2026

AGAMS Monthly Geology News — September 2026

Image courtesy of freepik.com, used under CC BY 4.0.

Gem of the Month: Peridot

Peridot is gem-quality olivine, typically found in yellow‑green to olive tones and valued as the traditional birthstone for September. It forms in silica-poor rocks and can also appear in meteorites, making it both a terrestrial and sometimes extraterrestrial gemstone.

  • Where Found: Peridot is gem-quality olivine found in silica-deficient rocks like volcanic basalt and in peridotite xenoliths from Earth’s upper mantle; it’s also found in some meteorites.
  • Fun Fact: Peridot is one of the few gemstones whose color is largely intrinsic to the mineral itself (the yellow-green comes from the olivine chemistry), rather than needing a “mysterious” color impurity like many other gems.

    • Image courtesy of Wren’s Nest / Dudley Bug educational materials, used for educational purposes.

    Fossil of the Month: Trilobite (Calymene type)

    Calymene trilobites lived in shallow Silurian seas, and their fossils are commonly found in places like Dudley, England and the Midwestern United States. They’re best known for their ability to roll up tightly like a pill bug, using their segmented exoskeleton as natural armor. This defensive trick makes them one of the most recognizable trilobites for students and collectors.

  • Where Found: Calymene trilobites are most commonly found in Silurian‑aged marine rocks across Europe and North America, especially in places like Dudley, England and the Midwestern United States.
  • Fun Fact: Calymene trilobites are famous for their ability to roll up tightly like modern pill bugs, using their segmented exoskeleton as natural armor.

    • Earth Science News — September Highlights

    • 567‑million‑year‑old fossil site in Canada’s Northwest Territories that pushes the origin of complex animal life back by 5–10 million years. These fossils show that early animals were already moving, reproducing sexually, and developing complex body plans much earlier than scientists believed. 
      Read more
    • Scientists have confirmed that the North Pole Dome in Western Australia is Earth’s oldest known impact crater, formed by a massive asteroid strike about 3 billion years ago. This makes it the only verified impact structure from the Archean Eon, a period when Earth’s earliest continents were just beginning to form. 
      Read more
    • A lunar meteorite called NWA 12593 contains evidence of three ancient asteroid impacts, including a colossal strike 3.5 billion years ago that melted the Moon’s surface into a vast lava sheet. This makes the meteorite a rare “three‑body record” of bombardment across the Moon, Earth, and asteroid Vesta during a violent era of Solar System history. 
      Read more

    🎒 Kids Corner Mini Activity September

    Kids Corner Mini Learning Lesson: The Rolling Fossil!

    Calymene trilobites lived in ancient oceans more than 400 million years ago, and they had a clever way to stay safe. When danger approached, they curled their bodies into a tight little ball — just like a modern pill bug. This rolling trick protected their soft underside and made them harder for predators to grab.

    Mini Activity: Try the Trilobite Trick!

    • Roll‑Up Practice — Have kids pretend they’re trilobites by kneeling and curling into a ball.
    • Armor Check — Ask them what parts of their body feel protected when they curl up.
    • Ocean Imagination — Let them imagine they’re on the sea floor, hiding from ancient predators.

    📅 Upcoming Events

    • Monthly Meeting: Friday, September 18, 2026