Fluorite Hummingbird on Pink Tourmaline 3b34b75217acce59401b324780a0e611 Trilobites are are important as

Trilobites are are important as paleo-zoic guide fossils

eurypterid fossils are uncommon in the fossil record because of the special conditions needed for preservation of their exoskeleton that was not mineralized

such as quartz) during a process called permineralization / replacement

the Left & Right Pleural Lobes and the middle Axial Lobe

Not to be confused with "Cubic zirconia

Fluorite Hummingbird on Pink Tourmaline 3b34b75217acce59401b324780a0e611 Trilobites are are important asFluorite is the "State Mineral" of Illinois. Fluorite forms in a variety of colors and is transparent to translucent in clarity. The chemical composition of Fluorite is CaF2, (calcium & fluorine.) The variation in colors are due to trace amounts of other elements replacing the calcium during the crystalline formation. Fluorite is used in a variety of industrial purposes and the overwhelming percentage of Fluorite in the United States was mined in