The Crom dimension stone occurrence is located on a west facing slope, east of Crowman Creek and at an elevation of approximately 750 metres.

The area is underlain by rocks of the Vernon Batholith, part of the Jurassic Island Plutonic Suite. The batholith consists of homogeneous body of medium- to coarse- grained plutonic rocks ranging from biotite-hornblende quartz diorite to leuco-quartz monzonite.

Locally, a flat-lying zone of grey-brown-pink granite gradationally overlays a dark-grey stone.

The dark-grey granodiorite is the dominant rock type and consists of a medium-grained, equigranular, dark grey, hornblende-biotite granodiorite. The constituents are: 5 per cent anhedral (5 to 7 millimetres) cream K-feldspar, 60 per cent anhedral (5 to 7 millimetres) grey-white plagioclase, 20 per cent anhedral grey (5 to 10 millimetres) quartz and 15 per cent black (5 to 8 millimetres) mafics, predominantly hornblende. The stone exhibits a fresh, clean, uniformly dark-grey appearance on newly exposed surfaces, showing little sign of alteration. Xenoliths are common at this location, ranging from less than 1 per cent to more than 25 per cent of the stone, though typically in a concentration of 1 to 2 per cent. The inclusions range in size from 2 to 10 centimetres and generally show a rounded character.

The main outcropping of this stone is along the spur road, where a 25 metre outcrop area displays regular fracture spacing producing natural 22.7 to 45.4 tonne blocks of stone. This stone also outcrops in the two road ballast pits.

The grey-brown-pink granite is confined to exposures in the upper most road pit. It consists of 40 per cent anhedral (2 to 4 millimetres) brown-pink K-feldspar, 30 per cent anhedral (2 to 4 millimetres) grey-white plagioclase, 20 per cent anhedral (2 to 4 millimetres) grey quartz, and 10 per cent anhedral (2 to 4 millimetres) black hornblende. As with the dark-grey stone, weathered surfaces show no signs of rusting or other deleterious substances. Unlike the dark-grey stone, no xenoliths were noted in this phase, supporting the view that it may be a sill.

The stone outcrops over a vertical distance of at least 5 metres and a horizontal distance of at least 25 metres in the upper ballast pit.

In 1994 and 1995, Mammoth Geological completed programs of geological mapping and minor test splitting of available material. The stone is reported to take a good polish and at least 363 tonnes of loose stone blocks have been identified in the two former road quarries (Assessment Report 24346).