Follow us

Image Alt

Petoskey Stones and Beach Glass

May 29, 2020 at 9:31 am

Petoskey Stones and Beach Glass

Looking for something to do Up North that is fun and family friendly?


With Up North opening slowly and social distancing, it may seem that activities are limited Up North, but there is still plenty to do! We have mentioned before the trails Up North, many with spectacular views and have mapped out the historical markers to learn about the area. Another fun adventure for adults and kids and easy to maintain social distancing is exploring area beaches for Petoskey stone and beach glass.


A Petoskey stone is a fossil colonial coral that lived in the warm Michigan seas during the Devonian time around 350 million years ago. Read more about Petoskey stones at Petoskey Stones, History, Lore and Facts.

Petoskey StonesThe most popular place for hunting Petoskey Stones is a Lake Michigan beach. Although the beaches are the hot spots, those ancient glaciers spread the fossils around and rockhounds know to leave the lakeshore to search cut roadbeds, gravel pits and even farmer’s fields.

Dry Petoskey Stones usually look like ordinary limestone in a color range from light grey to dark grey. The distinctive, six-sided “rays of the rising sun” pattern pops when the rock’s surface is wet, which is why it is easier to spy Petoskey stones along the shore or by wading out into the water. If you are hunting in a dry area carry a water bottle to spray your stones to bring out that pattern.


Beach glass (also known as Mermaid tears) can be found along the Lake Michigan shoreline and is broken shards of glass that have been smoothed as the result of years of tumbling and rubbing against rocks and sand in fresh water. After years of tumbling in Lake Michigan which acts like a giant rock tumbler the once sharp pieces are ground down and rounded. Some will still have the translucent color; others take on a softer frosted look.

Where does it all come from? Mostly, the glass has been discarded into the water on purpose from commercial and recreational boats, old factories that were on the shorelines and years ago from trash being dumped in the lake.

The color of beach glass is determined by the source and will be the same color it was before it was in the water. However, there are exceptions. A clear glass piece containing manganese will turn amethyst in color when exposed to the sun. More manganese, the more purple the glass gets. The most common colors are various shades of white, brown and light blue with green, dark blue and purple being rare. Finding red beach glass is exceedingly rare.

Purple Beach GlassHow can you tell if you have found is beach glass or just a pebble? At times it is hard to tell the difference between certain pebbles and beach glass. The easiest way to tell is to wet it thoroughly and you will be able to see more light through the glass evening and it will be noticeably clear. There are exceptions, milk glass, jadeite, insulators, some marbles, ceramics, and other semi-transparent glass are not clear, but still considered beach glass if the edges have been smoothed by the water.


The best time to find beach glass or Petoskey stones is early spring after the ice on Lake Michigan has melted along the shore. Each year as the ice is broken up and the winds push the ice in different directions, it pushes a new crop of Petoskey stones and beach glass towards the shores. The best time to find the stone in the summer is after a big storm. The big storm gets the water all crazy and such. Those wild waves mean lots of fun beach finds, so as soon as the crazy storm subsides you should head to the beach.

Beach Glass on rocky beachYou have explored the beaches, found beautiful Petoskey stones and beach glass, what do you do with your haul? Filling decorative jars and bowls or adding them in your potted plants is great way to add color and memories to your home. You can make jewelry, create mosaics or glue a magnet and stick them on your fridge or just put them back on the beach for another lucky hunter to find.

Walking the beach looking for Petoskey stones or beach glass is a wonderful way to relax and get outside. It is a family friendly activity that all ages enjoy. For a comprehensive list of area beaches click here and share your pictures on our Facebook page.


You don't have permission to register