DESCRIPTION: Dark brown powder, insoluble in water and soluble in mineral acids.
DESCRIPTION: Dark brown powder, insoluble in water and soluble in mineral acids.
形状颜色特性：黑褐色粉末，不溶于水，易溶于无机酸。
DESCRIPTION: Dark brown powder, insoluble in water and soluble in mineral acids.
形状颜色特性：黑褐色粉末，不溶于水，易溶于无机酸。