When the Smithsonian's gallery was renovated in 1997, the necklace was moved onto a rotating pedestal inside a cylinder made of thick bulletproof glass in its own display room, adjacent to the main exhibit of the National Gem Collection, in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals. The Hope Diamond is the most popular jewel on display and the collection's centerpiece. In 1988, specialists with the Gemological Institute of America graded it and noticed "evidence of wear" and its "remarkably strong phosphorescence" with its clarity "slightly affected by a whitish graining which is common to blue diamonds." A highly sensitive colorimeter found tiny traces of a "very slight violet component" which is imperceptible to normal vision.