To help you identify them, various Texas rocks and minerals are listed
together in the following charts according to properties that they have
in common. Although useful, the identification charts may not always
give you perfect results. For example, hardness, which is used as a
guide, is not to be completely relied upon in the identification of
rocks.
The charts on the following pages pertain only to the rocks and minerals
that are described in this book. It is quite possible that you will find
rocks and minerals in Texas that are not included in these charts.
If you find a rock or a mineral that you are unable to identify, you can
check your local library for reference books that may aid you (several
such references are noted on pages 100-101). If you need further help,
possibly the science teacher at a nearby public school will be able to
identify the specimen for you. Or if a college or university is located
in your area (especially one that has a department of geology), you can
obtain help there. In Texas, the Bureau of Economic Geology is a mineral
information center. Most other states have similar geological research
and public-service organizations. Other sources of information might be
the gem and mineral societies that are found in a number of communities.
Many of the members of these organizations are experts in the
identification of rocks and minerals.