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Black Opal, White Opal and Crystal Opal
Gilson-like Opals with a Play-Of-Color in Green or Orange
Gilson Opal Samples: Gilson Opal Shop
Gilson-like Opal
Rough Resin Free Created Opals Opals with a Green or Multicolored Pattern of Play-of-Color.Gilson-like Opals - Details and Description
Resin Free Opals with a Directional Pattern of Play-of-Color
Gilson-like opals are available as rough opals in different colors as black opals, white opals and crystal opals with orange or green fire.
They will be delivered as fragments in different sizes and weights.
This new type of Gilson created opal shows a columnar pattern typical for opals grown by sedimentation, but the opals are not impregnated with polymer. They are resin free and have the same chemical and physical properties as their natural occuring counterparts. Due to the lack of water, the opals are high temperature stable and suitable for glass blowing. Seven color combinations are available: White/Multicolor, White/Red, Black/Green, Black/Multicolor, Crystal/Green, Crystal/Multicolor and Black/White banded opals. The banded opals are unique, showing a layer of white opal between layers of black opal on top and bottom.
Gilson-like Opals - Description and Properties
- Opal: Type 2, Heterogeneously Crystallized
- Body Color: Black or White
- Play-of-Color: Multicolored, Dominant Green, Orange
- Opal Pattern: Columnar, Striated
- Opal Varieties: Black Opal, White Opal & Crystal Opal
- Specific Gravity: 2.18 - 2.25 g/cm3
- Index of Refraction (RI): 1.46 - 1.48
- Porosity: Non-Porous
- Temperature Resistance: up to 1100°C
- Hardness (Mohs): 6.5
- Composition: 100% SiO2
- Form of Delivery: Rough Opals
- Shape: Irregular Fragments in Different Sizes and Weights
- Thickness: 8 - 16 mm
- Coefficient of Expansion (COE): 30.5 - 33
- Gilson-like opals compatible with borosilicate glass
- Opals made of pure silica and suitable for sustainable jewelry
Gilson Opal
Rough Resin Free Created Opals Available Varieties
Gilson-like Crystal Opal - No. 4
Crystal Opal, Opal Fragment (Pictures)
Gilson-like Black Opal - No. 5
Black Opal, Opal Fragment (Pictures)
Gilson-like Black Opal - No. 6
Black Opal, Opal Fragment (Pictures)
Banded Gilson-like Opal - No. 7
Opal Fragment (Pictures)
Gilson-like Opal, Crystal Opal - No. 3
Crystal Opal, Opal Fragments (Pictures)About Gilson Opal
According to Darragh & Perdrix, the arrival of Gilson ‘synthetic’ opal in the marketplace was announced in 1972 by a New York jeweller who stated this opal would be available for sale in early 1973.
Later production runs of Gilson white, crystal and black ‘synthetic’ opals gradually improved the visual appearance of these opals to such an extent that while the distinctive ‘lizard skin’ appearance of this synthetic opal has never been removed, it is often cunningly disguised by cutting cabochons at an angle to their basic columnar structures.
Gilson Opal - Literature
35 years On - A New Look at Synthetic Opal, Australian Gemmologist (2003), 21, 11, pp. 438-447.
• Microstructure and mechanical properties of synthetic opal: A chemically bonded ceramic, Journal of Materials Research (1986), 1, 5, pp. 667-674.
• Gilson Created Fire Opal Imitation with Play of Colours, Journal of Gemmology (1984), Vol. 19, No.1, p43.
• An investigation of the synthetic products of Gilson showing a play of colours, Journal of Gemmology (1984), 19, 1, pp. 27–42.
• Untersuchung der neuen Opal-Imitation von Gilson, Zeitschrift der Deutschen Gemmologischen Gesellschaft (1983), 32, 2/3, pp. 119-125.
• Eine Untersuchung der opalisierenden Syntheseprodukte von Gilson, Zeitschrift der Deutschen Gemmologischen Gesellschaft (1983), 32, 2/3, pp. 107-118.
Internal structures and identification of Gilson synthetic opals, Journal of Gemmology (April 1976), 6, pp. 66-75.