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The Journal of the Royal Institute of Thailand Volume III - 2011 121 Somchai Bovornkitti Our study was conducted on four brands of vermiculite materials imported by Thailand from the Netherlands, the United States of America, Denmark, and Australia. Two methods were used in the study, namely, x-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results were that about half the specimens examnined by XRD contained asbestos-like material, but all the specimens were negative for asbestos when using SEM. For technical reasons, the present methodologies may not be absolutely effective in identifying asbestos fibres embedded in thick layers of these materials. Further studies is in progress. Figure 8. XRD record Figure 9. Picture of SEM 113-125_mac9 5/10/12, 1:35 AM 121