The examination was carried out using the diagrams of A. K. Boldyrev. The examination was conducted as follows (see the article). It was found that the discrepancies do not exceed 1/2°; in some cases, with very small ∆g and ∆p, the reading accuracy dropped to 1°, but the latter was rare. During the examination, large discrepancies were discovered between the values of 2V given by Larsen and the 2V obtained from the diagrams (see the article). A total of 380 minerals were examined.