The phosphate mineral apatite is widely distributed in all rock types, but is usually just small disseminated grains or fragments. Large well-formed crystals can be found in some contact metamorphic rocks. Very gemmy crystals of apatite like this deep green, fractured crystal on an orange-colored calcite matrix can be cut as gems but the softness of apatite prevents wide distribution or acceptance of apatite as a gemstone. The cryptocrystalline variety that makes up the rock phosphorite is called collophane.
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Download Open-File Report 95-681 as a PDF file (2.2 MB).
Download the Phosphate and Natural Aggregate Datasets in compressed tar (covers.tar.Z) Arc/Info Export format: (20.2 MB) download file, 45 MB uncompressed).
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Download Text and AML files needed to re-create the paper maps in a GIS. This file is in UNIX compressed tar format (amls.tar.Z) and includes 12 ASCII files of Arc/Info plot AMLs, key and text files, and explanatory text (11 kb download,33 kb uncompressed).
Download Maps prepared from the digital dataset, in compressed tar (maps.tar.Z) HPGL2 format (2 MB download file, 4.6 MB uncompressed HPGL2). The map scale is 1:2,000,000. Page size is approximately 29 by 38 inches. The map sheets are oriented with the long axis in the x-direction for plotting. These maps (phos2m.hp and sg2m.hp) were designed to be plotted on a HP Inkjet Plotter (model 650-C), but can be plotted on any full-color (inkjet or electrostatic) plotter that will accept HPGL2 code.
For questions about the scientific content of this report, contact Art Bookstrom
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Updated: August 28, 2007 (bwr, mfd)