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angular

	definition	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).
	source	Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119
	type	Resource Concept
	in scheme	particleshape has top concept angular anhedral diffuse euhedral resorbed rounded shape not specified sub angular sub rounded subhedral
	top concept of	particleshape

anhedral

	definition	Crystalline particles in a rock lack well-developed crystal faces, usually referring to igneous or metamorphic grains
	source	MacKenzie, W.S., Donaldson, C.H. & Guilford, C., 1982. Atlas of igneous rocks and their textures. John Wiley & Sons, New York
	type	Resource Concept
	in scheme	particleshape
	top concept of	particleshape

any shape

	definition	Shape property may have any value. Use in normative definitions where shape may take any value.
	source	this vocabulary
	type	Resource Concept
	in scheme	particleshape
	top concept of	particleshape

diffuse

	definition	Particles in aggregate have diffuse, ill-defined boundaries
	source	SLTTs 2004
	type	Resource Concept
	in scheme	particleshape
	top concept of	particleshape

euhedral

	definition	Crystalline particles in a rock are mostly bounded by perfect crystal faces, usually referring to igneous or metamorphoc grains
	source	MacKenzie, W.S., Donaldson, C.H. & Guilford, C., 1982. Atlas of igneous rocks and their textures. John Wiley & Sons, New York
	type	Resource Concept
	in scheme	particleshape
	top concept of	particleshape

resorbed

	definition	Particles have smooth, embayed boundaries caused by resorption by the host magma
	source	Neuendorf, K.K.E, Mehl, J.P. & Jackson, J.A. (eds), 2005. Glossary of geology, 5th Edition. American Geological Institute, Alexandria, 779 p.
	type	Resource Concept
	in scheme	particleshape
	top concept of	particleshape

rounded

	definition	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.
	source	Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119
	type	Resource Concept
	in scheme	particleshape
	top concept of	particleshape

sub angular

	definition	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).
	source	Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119
	type	Resource Concept
	in scheme	particleshape
	top concept of	particleshape

sub rounded

	definition	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).
	source	Powers, M. C., 1953 A new roundness scale for sedimentary particles. Journal of Sedimentary Petrology, v. 23, p. 117-119
	type	Resource Concept
	in scheme	particleshape
	top concept of	particleshape

subhedral

	definition	Crystalline particles in a rock are partly bounded by crystal faces, usually referring to igneous or metamorphic grains
	source	MacKenzie, W.S., Donaldson, C.H. & Guilford, C., 1982. Atlas of igneous rocks and their textures. John Wiley & Sons, New York
	type	Resource Concept
	in scheme	particleshape
	top concept of	particleshape