Michiana Gem and Mineral Society

04/08/2026

10/05/2025

✨ Mark your calendars for a day the whole family will love! ✨

Join us Saturday, October 11, 2025, at 211 Crystal Ridge Lane, Jessieville, AR, for our 12th Annual Family Fun Day at Ron Coleman Mining! As a proud 5th-generation, family-owned quartz crystal mine, we love watching toddlers to great-grandparents bond over the excitement of crystal digging.

🌟 Event Highlights:
💎 $5 off adult crystal digging fees
🎁 Hourly prize giveaways
🌭 Free hot dogs from 11 AM–1 PM
🏕 Book your stay at our on-site campground: crystalridgervpark.com

Start a new family tradition — or keep a treasured one going — this October. Visit our page for photos from last year’s celebration! 📸 Ron Coleman Mining

09/18/2025

Mark your calendar!

09/12/2025

Geology is the scientific study of the Earth's structure, composition, processes, and history, including rocks, minerals, and life forms. Also known as Earth Science, it examines how the planet formed and changed over billions of years, providing crucial information for resource management, hazard assessment, and understanding our world.

09/08/2025

Want to help us move AND get a free map?

The IGWS Store will be temporarily closing in October as we move to a new building. All online orders through the end of September will receive a FREE bedrock and Quaternary geologic map of Indiana!

Shop the IGWS Store for a unique selection of geology-themed books and gifts. Everything is $40 and below and purchases help fund our outreach programs. See more at https://store.igws.indiana.edu/.

09/05/2025

Here’s our quick list of some of the most dazzling special optical effects, called phenomena, in the world of gems:

- Asterism / Star Gem: When light hits tiny needle-like inclusions just right, gems like sapphire and ruby can show a mobile star pattern on their surface.
- Cat’s Eye (Chatoyancy): A single bright band of light stretches across the gem, like the slit pupil of a cat. Most famous in chrysoberyl, it can also appear in moonstone, emerald and tourmaline.
- Labradorescence: A dramatic flash of iridescent blue, green or gold seen in labradorite. Caused by layers of feldspar inside the stone scattering light.
- Play-of-Color: The rainbow fire seen in precious opals. Caused by microscopic spheres inside the gem that diffract light like a prism.
- Adularescence: A soft, floating sheen (often bluish) that hovers just beneath the surface of moonstone.
- Iridescence (called Orient in pearls): A rainbow-like shimmer that drifts across the surface. Common in pearls, fire agate, and ammolite.
- Color Change: A gems color appears different under varying light. Most famously seen in alexandrite, which can shift from red to green, but can also occur in sapphires and garnets.
- Aventurescence: A glittery, metallic sparkle caused by tiny mineral inclusions. Most famously seen in aventurine quartz and sunstone.

Which phenomenal gem is your favorite?

Read in-depth articles about each gemstone phenomena in the Summer 2025 edition of Gems & Gemology: https://bit.ly/4fLRzE9

09/03/2025

08/31/2025

Handy graphic on common rock identification 👍🏼
Edit: I can’t find the original link to the graphic but I found a site with a lot of helpful resources to identifying rocks and minerals that includes this graphic (linked in comments!)

08/25/2025

From this to this. Video doesn’t do it justice but has blue, green, and red down one side.

08/18/2025

And that’s a wrap for the MGMS 2025 show. THANK YOU to all of our amazing vendors, club volunteers and everyone who came out to the show. We hope you had a wonderful time, found some great treasures and enjoyed our show. See you next year!

08/16/2025

Just a few pictures from the show today. So many awesome specimens, jewelry, and more. Come on out this weekend starting at 10am.