Nature and Science Programs at Wonder Works


Find Crystals
February 19, 2015, 10:43 am
Filed under: Uncategorized

Here are photos of the take-home crystal collections we made at the February 20th Find and Make Crystals program at Wonder Works. Visitors could either glue the crystal specimens to a card at the museum and take that home, or take the crystals and card home in a plastic bag.

This card had labeled spaces for six types of crystals visitors could find and take home with them:

CrystalCard

Keep scrolling down to the bottom of this page to see close-up photos of the six types of crystals on this card.

This next card was designed to show that many types of rocks are made of one or more types of crystals. The example on this card, pegmatite, includes three types of crystals: white mica, pink feldspar, and quartz:

PegmatiteCard

Click here to learn more about pegmatite.

The third type of specimen visitors could collect at this program were pieces of geode, which were found in southwest Illinois:

GeodePiecesIllinois

The two specimens on the left in this photo show the dull-looking outside of the geodes. The two pieces in the middle show the tiny quartz crystals that line the insides of most of the broken geodes. The geode piece on the lower right shows calcite crystals, which we found in a few geodes. The upper right specimen shows the coating of white clay found in some of our geodes.(This kind of clay is made of crystals so small that they are hard to see even with a microscope.)

Click here to learn more about the geodes found in Illinois.

Click here to learn about one place you can collect geodes in Illinois.

Finally, here are photos that show some of the variations in the six types of crystals on the collection card that we showed at the top of this post.

Specular Hematite, Michigan

SpecularHematiteMichigan

Specular Hematite is a type of iron ore made up of tiny, shiny, flattened crystals of hematite. The specimens passed out at Wonder Works came from the iron-mining region of Upper Michigan. Click here to learn more about the mineral hematite.

Quartz Crystal, Arkansas

QuartzCrystalsArkansas

These tiny quartz crystals were dug out of dirt collected in the Ouachita Mountain area of Arkansas. Although the crystals are very small, some of them show well-formed crystal faces, and some even have points at both ends of the crystal. Once the dirt is washed off them, these crystals should look shiny and beautiful. Click here to learn more about Arkansas quartz.

Selenite Crystals, Oklahoma

HourglassSeleniteOklahoma

Selenite is a crystal form of the mineral gypsum. These particular selenite crystals are a very special variety from the Salt Plains region of Oklahoma. The crystals grew inside the salty, sandy soil of this region, trapping sand inside the crystals. Because the sand often forms an hourglass-like shape inside the transparent crystals, this variety is called Hourglass Selenite. Growing crystals sometimes bumped into each other, forming interlocked shapes.  Click here to learn more about Hourglass Selenite.

White Mica, Colorado

MicaColorado

These mica crystals grew from melted rock, welding together and interlocking with other crystals to form the rock known as pegmatite.  Mica crystals break very easily in certain directions, so that you can peal off very thin pieces. The thin mica pieces are clear and flexible. White mica is also called muscovite. Click here to learn more about mica.

Pink Feldspar, Colorado

FeldsparColorado

These feldspar crystals grew from melted rock, welding together and interlocking with other crystals to form the rock known as pegmatite.  Feldspar crystals tend to break in certain directions to form flat, somewhat shiny surfaces called cleavage planes, which you can see on the specimen in the upper right of this photo. This variety of feldspar often has a salmon pink color to the freshly broken crystals. Click here to learn more about feldspar.

Quartz, Colorado

QuartzBrokenColorado

This form of the mineral quartz grew from melted rock. The growing quartz crystals bumped up against other growing crystals, welding together and interlocking to form the rock known as pegmatite.  Although you can’t see the outer shapes of the quartz crystals (as in the Arkansas quartz shown above), these samples still have the ordered arrangement of silicon and oxygen atoms that make up quartz. Click here to learn more about quartz.

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