An Object in which every part is similar to every other in every relevant respect. More precisely, something is a Substance when it has only arbitrary pieces as parts - any parts have properties which are similar to those of the whole. Note that a Substance may nonetheless have physical properties that vary. For example, the temperature, chemical constitution, density, etc. may change from one part to another. An example would be a body of water.
||boulder||Boulders are Rock fragments larger than 256 Millimeters in approximateDiameter on the Wentworth Scale.|
| ||coal||Coal is a black or brownish black solid combustible substance formed by the partial decomposition of vegetable matter without free access of air and under the influence of moisture and often increased pressure and temperature. Coal is a sedimentary rock containing a high proportion of carbon.|
| ||cobble||Cobbles are Rock fragments between 64 Millimeters to 256 Millimeters in approximateDiameter on the Wentworth Scale.|
| ||marble||A metamorphic Rock that is used in Constructing and in creating Sculptures.|
| ||pebble||Pebbles are Rock fragments between 2 Millimeters to 64 Millimeters in approximateDiameter on the Wentworth Scale.|
| ||stone||A Stone is any small fragment of rock or mineral matter.|