Coloured gems or patterned stones, discreetly glued to thin glass dishes. The left one includes peridot, turquoise and sodalite; I think this one will work in 1:24 and 1:12 scales. The middle one includes amethyst, rose quartz and garnet. The right dish contains agate and leopardskin agate.
Left, greens & blues: 7/16 inch (1.1 cm) wide and just over 1/4 inch (0.6 cm) deep.
Centre, pink & purple: 9/16 inch (1.4 cm) and 7/16 inch (1.1 cm) deep.
Right, patterned agates: 9/16 inch (1.4 cm) and 7/16 inch (1.1 cm) deep.