mid-ohio mineral and fossil club
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Join Us for the 2026 Gem, Mineral, Jewelry, Bead, & Fossil Show!
Mark your calendars for the Mid-Ohio Mineral & Fossil Club’s annual show, happening June 6th and 7th at the Richland County Fairgrounds! This year’s special theme is “Mineral Oddities & Pseudomorphs,” making it the perfect follow-up for anyone fascinated by our recent dive into the science of fossil replacements.
Whether you are a seasoned collector or looking for a fun family outing, there is something for everyone. Come browse our quality dealers, watch live demonstrations, and try your hand at geode breaking! We will have hourly door prizes, silent auctions, and a dedicated Kid Activity Zone to inspire the next generation of rockhounds.
We can’t wait to see you in Mansfield this June!
Come to the 2026 Mid-Ohio Mineral & Fossil Club Gem, Mineral, Jewelry, Bead, and Fossil Show
Richland County Fairgrond.
Fairhaven Hall
750 North Home Road
Mansfield, Ohio 44903
JUNE 6TH AND 7TH
Saturday 10AM – 6PM
Sunday 11AM – 5PM
Admission
Adulsts $5.00
Seniors $4.00
Children 6-16 $3.00
Children 5 & under – FREE
Scouts in Uniform – FREE
Display Items
Fossils are the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas, lakes and rivers. Fossils also include any preserved trace of life that is typically more than 10 000 years old.
Geodes on display
Geodes are spherical or egg-shaped rocks that contain hollow cavities lined with crystals. The name geode comes from the Greek word Geoides, which means “earthlike”.
Amethyst Crystal Geodes
Amethyst is crystalline quartz in colors ranging from pale lilac to deep reddish purple. With a relatively high hardness of 7, the February birthstone is a fine facetable jewelry gem for all purposes. Lower grades of material can be cabbed, carved, and made into a great variety of beads and other ornamental objects.
Mid-Ohio Mineral & Fossil Club Spotlight:The Science of Pseudomorphs with Tom Kottyan
Join Tom Kottyan for an in-depth presentation on the fascinating world of fossil replacements, pseudomorphs, and mineral oddities, recorded live at a Mid-Ohio Mineral & Fossil Club meeting. In this educational talk, Tom explains the complex geological processes that transform ancient biological structures into stunning mineral specimens. He shares pieces from his personal collection, passing around examples of cellular replacement, casts, and molds, while explaining the specific minerals—like quartz, dolomite, and pyrite—responsible for preserving these ancient relics.
This presentation is an excellent resource for rockhounds and club members looking to better understand the distinction between direct cellular replacement (like petrified wood) and general structural replacement (like geodized fossils).
Key Topics Covered:
[00:33] Cellular replacement in dinosaur bones and petrified wood.
[01:53] Colonial coral replaced by quartz and dolomite crystals.
[04:18] The formation of geodized fossils in Kentucky and Indiana.
[08:39] Tampa Bay coral replacements and fluorescent aragonite.
[10:59] Cast replacements in Horn coral and Petoskey stones (Hexagonaria).
[19:21] Pyritized cephalopods, brachiopods, and crinoid heads.
[27:08] Club Q&A: Preserving fragile shale ferns, mother of pearl in ammonites, and rainbow petrified wood.
About us
The purpose of our club is to create an interest in the study of the earth sciences and all lapidary
JOIN OUR CLUB
Come join the Mid-Ohio Mineral and Fossil Club to learn and share in study of our earth’s minerals and fossils.
