146 Subsurface Geologic Methods 



Terminology for Insoluble Residues 



Definitions of special terms as agreed upon by the Residue Confer- 

 ence of 1946 are given below in alphabetic order. 



Abundant dolomolds or oomolds: See "dolomoldic." 

 Anhedral: No crystal form developed. 



Beekite: Botryoidal, subspherical, or discoid accretions of opaque silica 

 replacing organic matter, generally white. 



Chalcedonic: Transparent to translucent; smoky; milky; waxy to greasy; 

 may be any color, generally buff or blue-gray; may be finely mottled. 



Chalky: Uneven or rough fracture surface; commonly dull or earthy; soft 

 to hard; may be finely porous; essentially uniform composition; resembles 

 chalk or tripolite. (Formerly referred to as "dead" or "cotton chert." This in- 

 cludes dull, unglazed porcelaneous material which grades into glazed por- 

 celaneous material of smooth chert.) 



Chert: Cryptocrystalline varieties of quartz, regardless of color; composed 

 mainly of petrographically microscopic fibers of chalcedony and/or quartz 

 particles whose outlines range from easily resolvable to nonresolvable with 

 binocular microscope at magnifications ordinarily used by geologists. Particles, 

 rarely exceed 0.5 mm. in diameter. 

 Clay: Fine material of clay size. 

 Clustered: See "oolith." 

 Concentric: See "oolith." 



Dolomold: Rhombohedral cavities in an insoluble residue. (Generally due 

 to the solution of euhedral dolomite or calcite crystals.) 

 Dolomoldic: Containing dolomolds. 



Skeletal with dolomolds: Residues with rhombohedral open- 

 ings in which the constituent material comprises less than 25 

 percent of the volume of the fragment. Openings vary from micro- 

 scopic to megascopic. 



Abundant dolomolds: Residues with rhombohedral openings 

 with the constituent material comprising from 25 to 75 percent 

 of the volume of the fragment. Openings vary from microscopic 

 to megascopic. 



Scattered dolomolds: Residues having rhombohedral open- 

 ings in which constituent material comprises more than 75 per- 

 cent of the volume of the fragment. Openings vary from micro- 

 scopic to megascopic. 

 Dolomorphic: Used for describing residues where there has been replace- 

 ment or alteration of dolomite or calcite by an insoluble mineral which assumes 

 the crystal form of the soluble mineral, thus filling a dolomoldic cavity. 

 Drusy: Clusters or aggregates of crystals, generally incrustations. 

 Euhedral: Doubly terminated crystals; unattached. 

 Free: See "oolith." 



Granular: Chert; compact, homogenous; composed of distinguishable re- 

 latively uniform-size grains, granules, or druses; uneven or rough fracture sur- 

 face; dull to glimmering luster; hard to soft; may appear saccharoidal. (This 

 type is frequently referred to as "crystalline.") 



Granulated: Grains or granules partly cemented or loosely aggregated; 

 saccharoidal; grades from angular to drusy; fine to coarse; particles rarely 

 larger than 0.5 mm. in diameter. 



Lacy: Residues with irregular openings in which the constituent material 

 comprises less than 25 percent of the volume of the fragment. 



Massive: See "oolith." Used also to include fine or coarse granular 

 anhydrite or gypsum. 



