Staurolite is a member of the neosilicate family of minerals, in the same subgroup as topaz and andalusite. It is opaque, ranging from red brown to black. Its name comes from the Greek "stauros," because it commonly contains twinned crystals, a term for two crystals overlapping in a symmetrical way. It is the official state mineral of Georgia. Staurolites are also called "fairy stones" because of a legend that they are the crystallized tears of fairies weeping after the crucifixion of Jesus Christ.
Instructions
Where to look
1. Look for staurolite crystals in mountainous regions with metamorphic bedrock. In the United States, the most highly prized specimens have been found in Virginia, Georgia, New Mexico and Massachusetts. Any part of the Appalachian or Blue Ridge Mountains is a good place to look. Fairy Stone state park near Martinsville, Virginia, is named for the staurolites found there. Visitors are allowed to take stones as long as they don't dig for them. Staurolite Canyon, near Taos, New Mexico, is another good destination. Fannin County, Georgia, is also a staurolite hotspot.
2. Look for other minerals which are often found with staurolite: almandine garnet, mica, kyanite, albite, biotite, tourmaline and muscovite. If you have permission to dig (which means not in a state or national park), use a pick to break apart schists and gneiss -- staurolites often form in conjunction with these types of metamorphic rock.
3. Seek out stream beds and other areas with lots of loose rocks.These are the best places to go because fresh staurolites are constantly being exposed by water erosion.
Identification
4. Look for small stones which seem to have a four-sided crystalline shape. The twinned "cross-shaped" crystals of a typical staurolite are at a 60- or 90-degree angle to each other.
5. Feel the surface of your mineral sample. It should be rough, and may have a swiss-cheese appearance. Its color is most commonly reddish brown to blackish brown, but can also be found in yellowish brown or even blue.
6. Scrape your mineral sample across a hard, unweathered surface. If you have a streak plate, this is the time to use it. If you don't, any unglazed porcelain tile, bowl, or vase will do. This technique is called "streaking." Whole minerals are often widely variable in color, but the finely ground powder which is left behind by streaking usually has a more consistent color. Staurolite streaks white or grey, though its hardness may make it difficult to streak properly. In this case, use a hammer or a file to crush or scrape some powder from the sample, and rub this on the streak plate.
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