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Micrograph, normal light (ICA)

Iwakuro (literally, stone black) or burnt malachite black. Forbes Pigment Collection 2-20-1 Polarized microscope, under normal light. Mounted with Lens Bond SK-9. Photo: Shiho Sasaki, 2004 Under microscopic examination, this malachite appeared to be natural malachite. It has the characteristic appearance with banding and fractured structures. Twinning was also seen under cross polarized light. Most of the pigment particles are blackened, and exhibit the evidence of heating such as a darkened band and cracks or a blackened surface. A few still maintained their green color in the interior of the particles. The name of the pigment and the results of examination indicate that this pigment was deliberately heated.