Grab Bag

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One of the free activities at the 2018 ESCONI Juniors booth was the ESCONI Grab Bag. When children arrived at the booth, they were given a brown paper lunch bag or egg carton. Children then could select one specimen from each of eight different rock, mineral, fossil, and shell specimens to add to their collection.

The rest of this page consists of close up photos, names, and additional information about the specimens that were included in ESCONI Grab Bags during the 2018 show. For each type of specimen we give as much information as we have about it. However, because some donors did not provide much information about their specimens (or that information was misplaced during storage), we sometimes don’t know where specimens were found or, for fossils, how old they are.

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SELENITE CRYSTALS:

Selenite is the crystalline  form of the mineral, gypsum. The selenite crystals available on Saturday are a special type called Hourglass Selenite:HourglassSeleniteOklahoma

Hourglass selenite crystals grew inside salty, sandy soil on the Salt Plains of Oklahoma, trapping sand inside the crystals. The sand often formed an hourglass-like shape inside the translucent crystals.. Growing crystals sometimes bumped into each other, forming interlocked shapes.  Click here to learn more about Hourglass Selenite.

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FLUORITE CLEAVAGE CRYSTALS:

Fluorite is the state mineral of Illinois. These specimens were collected near Cave-in-Rock, the most famous locality for Illinois fluorite. Fluorite crystals are often purple in color, but they can also be clear, white, or other colors. When crystals of fluorite break, they often make triangular shapes , called cleavage crystals.

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Go here to read more about Illinois fluorite.

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POLISHED ROCKS:

The polished rocks that were available on Saturday morning included a variety of agates and other minerals that had been run through a rock tumbler:

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Later on Saturday and Sunday, we added some other types of polished rocks to the mix:

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Click here to visit a page that identifies many common types of polished rocks.

Learn more about rock tumbling.

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TACONITE PELLETS:

Taconite is a processed form of iron ore. It is often transported by train through the Chicago area on its way from the Minnesota Iron Ranges to steel mills on southern Lake Michigan, so you can find spilled taconite along local railroad tracks.

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Read more about taconite.

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FOSSIL BRACHIOPOD SHELLS:

These fossilized “sea shells” lived long before the first dinosaurs roamed the earth. The brachiopod fossils available at the grab-bag table in 2018 are called Platystrophia. They lived during the Ordovician time period, about 450 million years ago.  The brachiopods that were available on Saturday and on Sunday morning were collected in Napoleon, Indiana. We ran out of those on Sunday just after noon, so we put out some very similar brachiopods that were collected on the Stonington Peninsula in Michican

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Brachiopod shells look a bit like clams and other bivalve mollusks, but they were formed by a very different type of sea animal. Learn how to tell brachiopod shells from bivalves.

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FOSSIL CORALS:

Corals are another type of animal with a hard skeleton that lived in ancient seas. The fossil corals we put out on Saturday morning were Devonian age, about 400 million years old.

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Later on Saturday we added some other ages of fossil corals to the mix. Some of these were about 450 million years old:

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Rather than living in colonies like many modern corals, these coral animals each grew their own skeleton, which was often shaped like a cow’s horn. That’s why many fossil collectors call these either “solitary corals” or “horn corals.”

Go here to learn more about fossil corals.

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FOSSIL TURTLE SHELL PIECES

By early Sunday afternoon we ran out of horn corals, so we substituted a new kind of fossil: pieces of fossilized turtle shell.

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We’re pretty sure these pieces of turtle shell were collected in a badlands area of either South Dakota or Nebraska. The fossils in these areas are about 40 million years old. (That’s after dinosaurs went extinct, but before the Ice Age.)

Go here to see a photo one of the most common turtle fossils found in the badlands of South Dakota and Nebraska.

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FOSSIL SHARK AND RAY TEETH:

The fossil teeth available in 2018 were collected in Morocco, a country in north Africa. There are eleven shark teeth are on the left of the photo, below, and four ray teeth on the right:

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The Moroccan sharks and rays lived near the end of dinosaur times, about 60 to 70 million years ago.

The Prehistoric Planet store has posters and postcards that may help you identify your find.

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SEA SHELLS:

The sea shells available at the grab bag table were a mix of univalves (like snails) and bivalves (like clams). We had two plates of shells on Saturday. The more colorful shells were less than a thousand years old, so most people would not consider them to be fossils.

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We also put out a plate with less colorful or “bleached” fossil shells that were dug out of a quarry rather than picked up on a beach. These shells are from animals that lived a few million years ago — before the Ice Age, but long after dinosaur times.

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NOTE:  We will be adding more specimens to this page during the next few days, as we add more specimens to the grab-bag activity. We will also add more information and links about these specimens as time allows, so be sure to check back here during the week after the ESCONI show.