Various scientists have formed their own theories to explain how the "20th century manufactured" anatase in the Vinland Map ink could have got into genuine medieval ink. The first was chemist Jacqueline Olin, then a researcher with the Smithsonian Institution, who in the 1970s conducted experiments which produced anatase at an early stage of a medieval iron-gall ink production process. Examination of her anatase by a colleague, mineralogist Kenneth Towe, showed that it was very different from the neat, rounded crystals found in the Vinland Map and modern pigments. Towe himself, a clay specialist, briefly considered the possibility that the anatase could have come from clay, where it is present in trace amounts, but on checking McCrone's data found no significant traces of clay minerals. Shortly before the Raman analysis was published, historian Douglas McNaughton based a mistaken theory about the ink around McCrone's emphasis on the chromium-rich black particle, having obtained unpublished data on the similar particles in Möller's report.