One of Opal's charms is her complex but beautiful play of color. Her light resembles the art of a master painter and every color has its own personality and expression. Her play of color is elegant and unique as if various colors such as blue, green, red and purple were flying simultaneously inside of the jewel. Her beautiful color is the product of silica (silicon dioxide) which reflects light among its particles.

Through Crescent Vert technology, thick homogeneous jewels can be created. Therefore, unlike natural opals, Created Opals can be cut in large sections.
Her internal water balance is very even, she is very hard, and her elegant color resembles “water opal.”

Comparison of Crescent Vert and Natural Jewels

Items		Opal		Black Opal
		Artificial Opal	Natural Opal	Artificial Opal	Natural Opal
Chemical Characteristics	Composition	SiO2・nH2O	SiO2・nH2O	SiO2・nH2O	SiO2・nH2O
	X-ray Diffraction	Amorphous	Amorphous	Amorphous	Amorphous
	Spectroscopic Analysis	Same as Natural Jewel	Particular Absorption of Opal	Same as Natural Jewel	Particular Absorption of Black Opal
Physical Characteristics	Crystal System	Amorphous	Amorphous	Amorphous	Amorphous
	Mohs Hardness	5.0～6.5	5.5～6.5	5.0～6.5	5.5～6.5
	Specific Gravity	1.90～2.23	1.90～2.20	1.95～2.20	1.98～2.20
Optical Nature	Transparency	Transparent-Semitransparent	Transparent-Semitransparent	Semitransparent-Opaque	Semitransparent-Opaque
	Refractive Index	1.440～1.465	1.440～1.465	1.440～1.465	1.435～1.455
	Ultraviolet Ray Examination	(Long Wavelength) Dark Blue Violet - Inert (Small Wavelength) Pale Blue - Inert	(Long Wavelength) Strong Blue White - Inert (Small Wavelength) Pale Blue - Inert	(Long Wavelength) Dark Blue Violet - Inert (Small Wavelength) Pale Blue - Inert	(Long Wavelength) Strong Blue White - Inert (Small Wavelength) Pale Blue White - Inert
	Special Effects	Play of Color	Play of Color	Play of Color	Play of Color