| Summary: | Although it is hazardous to attempt mineralogic or petrologic identifications of material from photographs, the excel lent quality of the color illustration accompanying Jim Stephan 's description of a "chlorite " pick bannerstone from Moore County, North Carolina (Stephan 1995) makes it almost certain that this artifact was manufactured from the min erai labradorite rather than from chlorite. Labradorite is a variety of plagioclase feldspar characterized by a striking cha toyant play of colors. Very frequently, like most plagioclases, it also displays mul tiple twinned crystals, known as albite twinning, which appears as fine parallel lines on a cleavage face. The pick ban nerstone found near Robbins, Moore County, North Carolina, exhibits both of these features, although a low power hand lens is necessary to discern the crystal twinning from the photograph. labradorite obtains its name from Labrador, where specimens exhibiting spectacular chatoyancy occur. Figure 1 is a polished specimen from the Orton Museum geological collections (Acc. No. 2197) collected by Jack Delong on St. Paul Island, labrador. Another specimen collected by Delong from Iceland (Acc. No. 2028) is shown in Fig. 2 and displays the fine ruled lines characteristic of albite twinning. The brilliant play of colors shown by this specimen is typical of the material from labrador, but examples from other locales have the chatoyancy much subdued or lacking. Labradorite does occur in North Carolina, and Pratt (1933: 158) reports it
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