We are Thailand based group of companies. Our main business today is to produce own glass-ceramic material Siamite. As professionals engaged in gemstone and mineralogy business for over 20 years we understood the demand of jewelry producers in some new material. Which will have the necessary properties missing in existing materials - uniformity of color like glass, and hardness, density, refractive index, and brilliance as in most natural gems.
Perfection of glass-ceramics and creation of Siamite was the result of research.
Not classifiable as glass or as crystal (mineral), glass-ceramics represent a completely new class of materials. Glass-ceramics are ceramic materials formed through the controlled nucleation and crystallization of glass.It is important to emphasize that this crystallization occurs precisely in a solid body – like the metamorphic recrystallization of rocks in the Earth's crust. We can say that an analogue of transparent glass-ceramics in nature can be partially crystallized obsidians and volcanic rocks.
Glass-ceramics are manufactured in two production steps. In the first step, a batch of exactly defined composition is melted and formed using standard glass manufacturing techniques. In the second step, the glass articles are subjected to a specific heat treatment to produce a glass-crystalline material with properties which are very different from those of original glass. This breakthrough hybrid material combines the valuable properties inherent in crystals and glass, which cannot be found in glass or crystals alone.
Glass-ceramics are developed and implemented in various fields of science and technology. Their composition is highly variable depending on the application and the required properties. Many applications of glass-ceramics are based on their superior resistance to failure due to thermal shock. It is primarily determined by the low thermal expansion coefficient both in the crystalline phase and in the residual glass. They are used for cookware, electric stove tops, telescope mirrors and missile radome (rocket nose cones).
It is known that many natural and synthetic crystals and glasses cannot be used for the "Setting Stones in Wax" method because they crack or change color under the influence of a high-temperature melt of gold, silver, bronze, or brass. Resistance to thermal shocks was the main reason that forced the author to develop and produce special glass-ceramics for the jewelry industry.
The second very important advantage of glass-ceramics is the relative uniformity and homogeneity of color; that is, from the absence of a significant color variation both in rough material and in faceted stones (with rare exceptions). This is due to the nature of this material, its composition and structure.