Lake Michigan Beach Rocks

A Sharkey Family Project (Meghan, Liam, & Erin)

Home:  Michigan City, IN

One of our family's favorite things to do is to visit Jay and Sheila O'Hara's lakehouse in Indiana.  We spend many hours each day at the beach, enjoying Lake Michigan.  One of our favorite things to do while at the beach is to look for beach glass, indian beads, and rocks.    This website is our attempt to identify the rocks and other collectables that people find as they walk along the beaches of Lake Michigan.  We also show unique items that we have been unable to identify.

Please see the page tabs on the top of the web page. We have included a "Favorite Places in the Area" tab for restaurants and other fun family locations that we recommend while in the New Buffalo, MI and Michigan City, IN area.

Our primary resource in identifying the rocks is the book " Lake Michigan Rock Pickers Guide" by Bruce Mueller & Kevin Gauthier.  If you want to learn more about Lake Michigan rocks , we recommend this book.

Beach Glass 

One of the most popular items to collect on the beach is glass that has been smoothed by the sand and waters of the lake.  There main colors are green, white (clear), brown, and the rare blue. 


A marine invertebrate, also known as a "sea lilies".  This animal is fixed to the sea bottom by a stalk and resembles a plant.  Sometimes called  "Indian Beads" by beach collectors. These crinoid fossils are from the Paleozoic Era (from 540 to 245 million years ago). 


A hollow mineral body found in limestone and some shale with a chalcedony layer surrounding an inner lining of crystals. The hollow interior often is nearly filled with inward-projecting quartz crystals. Before they are cracked open, geodes often look like "brains" with their bumpy texture.


Pure quartz comes in a variety of colors, the most common are a cream to yellow shade. They are normally smooth and transparent. Sand grains are mostly quartz and quartz is a primary ingredient in most stones.

Lightning Stones ---(called Giraffe rocks by Maria and Tess Rucoba)

Clay cemented into an iron mineral called siderite. The cracks fill with calcite brought in by ground water. The white lightning like patterns form in part through bacterial activity.


Blue Chert and Leland Blue Slag

Chert will come in different varieties of colors.  It is commonly confused with agate. To identifythe chert look for fractures and it is not transparent.  It sometimes looks tan to cream in color and blue chert is usually found in Leland Michigan. The chert has a grayer look than leland blue slag when they are both dry.                                                                                          Leland Blue Slag is a rich blue stone also found in Leland Michigan.  This stone is more than 100 years old and will have holes in them. Blue Slag looks almost the same as blue chert. 

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