James St. John: Herkimer Diamond quartz in dolostone (Little Falls Formation, Upper Cambrian; Middleville, New York State, USA)
James St. John: Quartz geode (Atlas Mountains, Morocco)
James St. John: Quartz with chlorite (Transylvania, Romania)
James St. John: Quartz (Silverton, Colorado, USA)
James St. John: Teredolites bivalve borings in fossil conifer wood (Windalia Radiolarite, Lower Cretaceous; Mooka Creek area, Kennedy Ranges, Western Australia)
James St. John: "Liesegang banding" in quartzose sandstone 20
James St. John: Gorman Nature Center (Mansfield, Ohio, USA) 1
James St. John: Gorman Nature Center (Mansfield, Ohio, USA) 2
James St. John: Gorman Nature Center (Mansfield, Ohio, USA) 3
James St. John: Gorman Nature Center (Mansfield, Ohio, USA) 4
James St. John: Gorman Nature Center (Mansfield, Ohio, USA) 5
James St. John: Gorman Nature Center (Mansfield, Ohio, USA) 6
James St. John: Gorman Nature Center (Mansfield, Ohio, USA) 7