Prized by collectors. Synthetic strontium titanate or fabulite found in a similar manner to perovskite. Natural counterpart of fabulite with the same composition is called tausonite.
The sum of homogeneous, physically distinct portion of matter in heterogeneous system, as the three phases; solid, liquid, or gas. Each phase may exist in different temperatures and pressures.
A special optical occurrence, or circumstance observed or are visible in certain gemstones such as chatoyancy, asterism, or play of color, adularescence, girasol, labradorescence, opalescence, schiller, etc.
Physical properties of gemstones are extremely important in understanding geological phenomena in synthesizing new materials, and identification of minerals. Physical properties and chemical composition of minerals change with temperature and pressure. P
Quantum of light or electromagnetic radiation, it can behave as a wave or as a particle. Traveling at the velocity of light. Photon have momentum but not mass or electrical charge. Also known as light quantum. Caused by excitation of atoms and molecules a
A variety of translucent, grayish-green to greenish yellow chatoyant quartz or chalcedony containing fine parallel fibers of asbestos or parallel channels, arranged through the stone at right angles to the eye and parallel to the base of the crystal, that
An unusual feature occur in Verneuil synthetic corundum by plunging of still heated stone into a much cooler liquid (thermal shock), which create fractures and it resemble closely to natural stone. By pursuing of this process developed honeycomb pattern d
An oily colorless, specific odor, insoluble, basic heterocyclic with the formula C9H7N. Composed synthetically by heating aniline, nitrobenzene, glycerol, and sulfuric acid. Used as food preservative and in the manufacture of dyes and antiseptics. R.I. -
The four quadrilateral facets of 8 main facets on the crown or on the pavilion of a brilliant-cut stone, which are also called bezel facets. The 4 on the crown touching the girdle with their apex and extending up to touch the table. There are four lozenge
The emission of particles or electromagnetic waves from a source such as nuclear radiation, X-rays, neutrons, gamma rays, electrons positive or negative, protons. Radiation has the effect of artificially altering color by artificially creating color cent
Radium treatment of minerals such as beryl to produce a bluish-white fluorescence only on the basal planes. Under SWUV and LWUV light beryl fluoresces bluish-white.
The turning back of wave from surface, on which they are incident according to the definite law of reflection. A small part of ray 17.2% of incident light striking the surface vertically is reflected from the surface (the 17.2% is upper limit of reflected
Several methods are available for the measurement of refractive indices such as refractometer for total reflection, immersion method in liquid for Beck effect, shadow method, and minimum deviation method.
Dioxide of silicon (SiO2), which appeared in five crystalline polymorphous such as quartz (alpha and beta), tridymite, cristobalite, coesite, and stichovite, in cryptocrystalline such as chalcedony and chert, and in amorphous such as opal (a hydrated sili
To simulate or imitate a natural gemstone, which is made from components that are easier, cheaper or more convenient to manufacture. Simulated stone having superficial appearance to the true stone but differs from it either in chemical composition, struct
The ratio of the weight of any substance to that of pure water at temperature of 3.98 C (39.2 F) degree and standard atmospheric pressure. Specific gravity of gems and minerals are determined by means by hydrostatic weighing method.
A small hand optical device for obtaining and visually observing spectrum, in which collimated light passes through a narrow slit onto either a prism or diffraction grating, its spectrum being viewed by a lens system or telescope. The angle between the c
Any array of electromagnetic visible light ordered according to its constituent wavelengths or colors, when the white light is dispersed by a prism or diffraction grating, ranging from about 750 to about 400 nm. The spectra can obtained by means of spectr
An isomorphous mineral of spinel group. A wide range of colors and shade of gemstone. Red-orange is named as flame spinel, an iron-rich dark-green to black, which is known as green spinel, pleonaste or ceylonite, grass-green as chlorospinel (iron-rich), b
SSEF laboratory offers analysis of precious stones and issue test reports for diamonds, coloured stones and pearls. It was recognized in 1978 by the International Confederation of Jewellers and Goldsmiths (CIBJO and also a member of the International Colo