URI	prefLabel	Definition	Source
http://resource.geosciml.org/classifier/cgi/particleshape/angular	angular	"A clastic sedimentary particle showing very little or no evidence of abrasion, with all of its edges and corners sharp, such as blocks with numerous (15-30) secondary corners and a roundness value between 0.17 and 0.25 (midpoint at 0.21)."	"Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119"
http://resource.geosciml.org/classifier/cgi/particleshape/anhedral	anhedral	"Crystalline particles in a rock lack well-developed crystal faces, usually referring to igneous or metamorphic grains"	"MacKenzie, W.S., Donaldson, C.H. & Guilford, C., 1982. Atlas of igneous rocks and their textures. John Wiley & Sons, New York"
http://resource.geosciml.org/classifier/cgi/particleshape/diffuse	diffuse	"Particles in aggregate have diffuse, ill-defined boundaries"	SLTTs 2004
http://resource.geosciml.org/classifier/cgi/particleshape/euhedral	euhedral	"Crystalline particles in a rock are mostly bounded by perfect crystal faces, usually referring to igneous or metamorphoc grains"	"MacKenzie, W.S., Donaldson, C.H. & Guilford, C., 1982. Atlas of igneous rocks and their textures. John Wiley & Sons, New York"
http://resource.geosciml.org/classifier/cgi/particleshape/resorbed	resorbed	"Particles have with smooth, embayed boundaries caused by resorption by the host magma"	"Neuendorf, K.K.E, Mehl, J.P. & Jackson, J.A. (eds), 2005. Glossary of geology, 5th Edition. American Geological Institute, Alexandria, 779 p."
http://resource.geosciml.org/classifier/cgi/particleshape/rounded	rounded	"A clastic sedimentary particle whose original edges and corners have been smoothed off to rather broad curves and whose original faces are almost completely removed by abrasion (although some comparatively flat surfaces may be present), such as a pebble with a roundness value between 0.49 and 0.70 (midpoint at 0.59) and few (0-5) and greatly subdued secondary corners. The original shape is still readily apparent."	"Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119"
http://resource.geosciml.org/classifier/cgi/particleshape/shape_not_specified	any shape	Shape property may have any value. Use in normative definitions where shape may take any value.	this vocabulary
http://resource.geosciml.org/classifier/cgi/particleshape/sub_angular	sub-angular	"A clastic sedimentary particle showing definite effects of slight abrasion, retaining its original general form, and having faces that are virtually untouched and edges and corners that are rounded off to some extent, such as a glacial boulder with numerous (10-20) secondary corners and a roundness value between 0.25 and 0.35 (midpoint at 0.300)."	"Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119"
http://resource.geosciml.org/classifier/cgi/particleshape/sub_rounded	sub-rounded	"A clastic sedimentary particle showing considerable but incomplete abrasion and an original general form that is still discernible, and having many of its edges and corners noticeably rounded off to smooth curves, such as a cobble with a reduced number (5-10) of secondary corners, a considerably reduced area of the original faces, and a roundness value between 0.35 and 0.49 (midpoint at 0.41)."	"Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119"
http://resource.geosciml.org/classifier/cgi/particleshape/subhedral	subhedral	"Crystalline particles in a rock are partly bounded by crystal faces, usually referring to igneous or metamorphic grains"	"MacKenzie, W.S., Donaldson, C.H. & Guilford, C., 1982. Atlas of igneous rocks and their textures. John Wiley & Sons, New York"
http://resource.geosciml.org/classifier/cgi/particleshape/very_angular	very angular	A clastic sedimentary particle with a roundness value between 0.12 and 0.17 (midpoint at 0.14).	"Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119"
http://resource.geosciml.org/classifier/cgi/particleshape/well_rounded	well rounded	"A clastic sedimentary particle whose original faces, edges, and corners have been destroyed by abrasion and whose entire surface consists of broad curves without any flat areas, specif. said of a particle with no secondary corners and a roundness value between 0.70 and 1.00 (midpoint at 0.84). The original shape may be suggested by the present form of the particle."	"Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119"