The complete catalog of transparent SIAMITE® gemstone reflections include about 780 different colors and shades (Fig. 4,5,6), along with more than 200 translucent and opaque varieties (Fig.7). They are part of 104 transparent color groups (groups of emeralds, blue topazes, sapphires, rubies, tourmalines...) and approximately 50 translucent and opaque groups (groups of turquoise, moonstones, lapis lazuli, jadeites...).
Figure 4. SIAMITE® reflections of the most common natural gemstones.
The ability to produce many colors, shades, and saturations is another unique feature of SIAMITE. This allows for the creation of a wide range of imitations of natural gems from different deposits: emeralds ranging from yellowish-green to bluish-green (Zambian, Brazilian, Colombian, and other types); sapphires from gray-blue to violet-blue (Australian, Ceylon, ...); amethysts from violet to purple-blue and purple (Brazilian, Uruguayan, ...); topaz (London Blue, Swiss, Sky Blue), and so on (Fig. 5).
And the abundance of choices in saturation enables the production of cut stones in any shape with consistent color, ranging from 0.8 mm to at least 20 mm (Fig. 6).
Figure 6. SIAMITE® Ruby reflections of different saturation - color group 1550-1559. Sizes of cut stones: round 1.3 and 5 mm, rose cut 8 mm, oval 8x6 mm.
The uniqueness of the properties of glass-ceramics allows for an unlimited range of varieties not only in color but also in transparency. This is achieved by controlling changes in the concentration and particle size of nanocrystals. The translucent and opaque SIAMITE® imitate decorative gemstones such as moonstone, cacholong, chrysoprase, jade, lapis lazuli, turquoise, black spinel, and others (Fig. 7). The hardness, density and resistance to thermal shock are approximately the same as those of transparent SIAMITE®.
It is important to consider that the degree of transparency is determined not only by the size and concentration of nanocrystals of spinel and other minerals but also by the thickness of the cabochon or cut stone. In other words, a stone that appears translucent, for example, at 3 mm will become almost opaque at 8-10 mm. Consequently, as the transparency of the stone decreases, its color gradually changes (Fig. 8).
Figure 8. Translucent and Opaque SIAMITE®. The transparency of cabochons in a row: 3-6-8-12 mm is gradually reduced.