Gillam 1970, type 310-1 (170-210; 180-200)
Type example:
South Shields, SS77, unstratified. Published: Bidwell and Speak 1994, fig. 8.6, no. 3. Brown core with orange margins and mid-grey surfaces. Soft black inclusions, and rare white quartz.
Other examples:
A. South Shields, 3826 (c.225). Dark grey core and surfaces with noticable fine white inclusions and rare large white inclusions.