What are the authenticity identification of writing stones?

Concave stones and convex stones are the most common forged objects. Mainly depends on whether the strokes of the characters are smooth, whether the charm of calligraphy is natural, whether the craftsmanship is heavy, and the traces of polishing and carving are common in fakes; The color and brightness of the characters and strokes of the relief stone are higher than that of the stone body, which is similar to the relief characters. The concave stone is the opposite; If the stroke shading of the concave stone is U-shaped, it is artificial. If it is V-shaped, it depends on whether there are traces of artificial polishing, and whether the contrast between color and stone surface is harmonious and natural.