Abstract
This is the first case of a talc pneumoconiosis not associated with tuberclosis or other diseases in Japan. The talc crystals were separated from the dried lung tissue after the Sundius and Bygdoen method, amounting over 10% in weight of the lung tissue. The crystals are prismatic or scaly in shape, and 0.004-0.016mm in length. Colorless and distinct cleavages. Refractive indices α=1.540, γ=1.585. X-ray diffraction pattern shows several peaks characteristic to talc. The chemical composition of this talc is shown in Table 3, and is compared with talcs from different localities in Table 4. The chemical formula of this talc is calculated as H1.70 Mg3.14 Si4.00 O12.00.
