ROCKS AND MINERALS AT THE EARTH SCIENCE EDUCATION NETWORK, KENTUCKY GEOLOGICAL SURVEY

One of the most basic earth-science concepts is that rocks and minerals have properties that allow for their classification and description. Unfortunately, the difference between rocks and minerals is not always understood by nongeologists. Sometimes rocks are described as having properties of hardness, streak, color, and luster, which are mineral properties, not rock properties. In Kentucky, the State Mineral is coal, which is scientifically a sedimentary rock. Although coal is a rock, legally and economically it is considered a mineral. Kentucky's State Rock is agate, which of course, is a variety of the mineral quartz.

In order to aid students and teachers in the identification of Kentucky's rocks and minerals, a Web site was developed as part of the Kentucky Geological Survey's Earth Science Education Network, www.uky.edu/kgs/education/education.html. The rocks and minerals part of the Web site was modeled after the popular book, "Rocks and Minerals of Kentucky." Minerals are sorted by common name and mineralogic group. Each mineral description contains photographs and information about the mineral's crystal system, cleavage, hardness, color, streak, luster, specific gravity, tenacity, occurrence in Kentucky, and economic uses, to aid inquiry-based education in the classroom. Methods for identifying minerals are also summarized. An identification key is being developed, as are searches by geographic area. Because many of Kentucky's most spectacular minerals are found in vein deposits, information about vein and other mineral deposits are featured. Pictures and descriptions of rocks used in lapidary are provided, including a picture gallery of the State Mineral, agate. Explanations of the State Mineral and State Rock, show how they were chosen and reinforce the definitions of rocks, minerals, and economic minerals.

A class exercise called "Minerals are the building blocks of rocks" has also been developed to help demonstrate the difference between rocks and minerals. In this exercise, colored building blocks representing minerals are used by students to build model rocks. Different combinations and sizes of mineral blocks are used and compared between students. These are then compared to actual minerals and rocks in the classroom.