Hyalite
A variety of Opal
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About Hyalite
Formula:
SiO2 · nH2O
Colour:
Colorless, white, creme-colored, yellow, orange
Lustre:
Vitreous, Sub-Vitreous
Hardness:
5½ - 6½
Specific Gravity:
2.0 - 2.2
Name:
Named from ύαλος ('glass') from its appearance, by A.G. Werner in 1794.
A colourless variety of Opal-AN, an amorphous silica-glass containing about 3-8% water.
Because it has a different structure, it does not show the opalescence (play of color) that is found in precious opal.
Hyalite occurs as globular and botryoidal masses and irregular crusts in volcanic and pegmatite environments where the silica deposits from the gas phase (Flörke et al, 1973). It often shows a strong green fluorescence in UV light.
The refractive index varies slightly with water content and lies between 1.44 and 1.46 (Graetsch, 1994). Hyalite is optically isotropic, but may show strain birefringence (Graetsch, 1994).
Visit gemdat.org for gemological information about Hyalite.
Because it has a different structure, it does not show the opalescence (play of color) that is found in precious opal.
Hyalite occurs as globular and botryoidal masses and irregular crusts in volcanic and pegmatite environments where the silica deposits from the gas phase (Flörke et al, 1973). It often shows a strong green fluorescence in UV light.
The refractive index varies slightly with water content and lies between 1.44 and 1.46 (Graetsch, 1994). Hyalite is optically isotropic, but may show strain birefringence (Graetsch, 1994).
Visit gemdat.org for gemological information about Hyalite.Unique Identifiers
Mindat ID:
32188 (as Hyalite)
3004 (as Opal)
3004 (as Opal)
Long-form identifier:
mindat:1:1:32188:4 (as Hyalite)
mindat:1:1:3004:1 (as Opal)
mindat:1:1:3004:1 (as Opal)
Pronunciation of Hyalite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Hyalite
Vitreous, Sub-Vitreous
Transparency:
Transparent, Translucent
Colour:
Colorless, white, creme-colored, yellow, orange
Comment:
No opalescence (play of color)
Streak:
White
Hardness:
5½ - 6½ on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Conchoidal
Density:
2.0 - 2.2 g/cm3 (Measured)
Comment:
varies with water content
Chemistry of Hyalite
Mindat Formula:
SiO2 · nH2O
Elements listed:
Geological Environment
Geological Setting:
Volcanic vugs, pegmatite pockets, fumaroles.
Other Language Names for Hyalite
Simplified Chinese:玻璃蛋白石
Common Associates
Associated Minerals Based on Photo Data:
| 31 photos of Hyalite associated with Schorl | NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH) |
| 22 photos of Hyalite associated with Quartz | SiO2 |
| 20 photos of Hyalite associated with Muscovite | KAl2(AlSi3O10)(OH)2 |
| 19 photos of Hyalite associated with Fluorite | CaF2 |
| 19 photos of Hyalite associated with Albite | Na(AlSi3O8) |
| 19 photos of Hyalite associated with Smoky Quartz | SiO2 |
| 14 photos of Hyalite associated with Scheelite | Ca(WO4) |
| 13 photos of Hyalite associated with Aquamarine | Be3Al2Si6O18 |
| 12 photos of Hyalite associated with Tourmaline | AD3G6(T6O18)(BO3)3X3Z |
| 12 photos of Hyalite associated with Aragonite | CaCO3 |
Fluorescence of Hyalite
May show strong green UV fluorescence
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Hyalite
mindat.org URL:
https://www.mindat.org/min-32188.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
References for Hyalite
Localities for Hyalite
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Afghanistan | |
| Jose Zendrera Collection |
Antarctica | |
| Collection of RJ Martin |
| Collection of RJ Martin |
Australia | |
| Porter (1894) |
| Sorrell (n.d.) |
| Kennon et al. (2009) | |
| Collection of RJ Martin |
| Sorrell (n.d.) |
| Derrick +1 other reference |
| Con Constantinides collection |
| Costas Constantinides |
| Sorrell (n.d.) |
| R Bottrill collection |
| Sorrell (n.d.) |
| Sorrell (n.d.) |
| Sorrell (n.d.) | |
| Sorrell (n.d.) |
| Sorrell (n.d.) |
| Sorrell (n.d.) |
Austria | |
| Mineralienatlas.de +1 other reference |
| Erwin Löffler collection |
Bolivia | |
| Pough (1976) |
Brazil | |
| Sauer (1982) |
| Sauer (1982) |
| de Brito Barreto et al. (2010) |
| Fernando Brederodes Collection |
Canada | |
| personal correspondence with Giles Peatfield (see comments) |
| Peatfield (n.d.) |
| Michael Adamowicz Collection |
| Shadow Lake RockHounders Facebook group |
China | |
| National Geological Archives of China ... |
Czech Republic | |
| Petr Fuchs collection |
| Pauliš P. et al. (2015) |
| P.Zeman et al. (2017) |
| P.Pauliš |
France | |
| Mboungou-Kongo (2002) |
| Müller et al. (2023) |
| Designolle (2021) |
| Baret (1905) |
| S. MAURY (S) |
| MAURY (S) |
Germany | |
| Weisenberger et al. (2014) |
| Hentschel (1976) |
| Volker Betz and Peter Lof collections ... | |
| Locality description | |
| Habel et al. (1994) |
| Habel (2006) |
| Jordan (1803) |
| Collection of Volker Betz +1 other reference |
| www.zobodat.at (2022) |
| Blass et al. (1992) |
| Juroszek et al. (Ti 5 Fe) |
Greece | |
| Locality description |
Hungary | |
| Society of Economic Geologists Student Chapter University of Miskolc (2018) |
| Locality description |
Indonesia | |
| Sujatmiko et al. (2007) | |
Italy | |
| Napoleoni et al. (2021) |
| Collection Giuseppe Finello |
| Curlo (1929) |
| Roggiani A.G. (1969) +2 other references |
| Bortolozzi (n.d.) |
| Stara et al. (1996) |
| Stara et al. (1993) |
| Bonifazi (2020) |
| Bonifazi (2020) |
| Bonifazi (2020) | |
Japan | |
| Yamada (2004) |
| Alfredo Petrov field trip observations |
| Amir Akhavan Collection |
| Yamada (2004) |
Mexico | |
| Panczner (1987) |
Namibia | |
| von Bezing (2007) |
New Zealand | |
| Collection of RJ Martin |
| Tim Saunderson collection |
| Collection of Rod Martin |
| Collection of RJ Martin |
| Tim Saunderson collection |
| Collection of RJ Martin |
| CF Johnson collection +1 other reference |
Norway | |
| Larsen (2024) |
| Nordrum (2015) |
Pakistan | |
| Jose Zendrera Collection |
| Ikram Mineralogy |
| imported from Shigar District +1 other reference | |
| Collection of Mike Howard |
Poland | |
| Lis et al. (1986) |
| Jäkel [F.W.?] (1853) | |
| Krzysztof Andrzejewski |
| Leopold von Buch 1802 - Geognostische ... +3 other references |
| Adamczyk Z. (2008) |
| Lis et al. (1986) |
| Schumacher K. (1878) +1 other reference |
| Lis et al. (1986) |
| Glocker E.F. (1829) |
| Lis et al. (1986) |
| Lis et al. (1986) |
| Roemer (1870) |
Portugal | |
| Schnorrer-Köhler et al. (1991) |
| Josep Sanchez-LaFuente i Mariol field ... |
Russia | |
| Skovitina et al. (2014) |
Slovakia | |
| Pavol Myšľan Collection +1 other reference |
| Duda et al. (1992) |
South Africa | |
| Atanasova et al. (2016) |
| SAMS (South African Micromount Society) |
Sweden | |
| Lorin (2022) |
Switzerland | |
| Schwanz et al. (1994) |
| Gorsatt (Ed.) |
USA | |
| Barwood (1974) |
| Scarborough (1981) |
| Scarborough (1981) | |
| Frank Karasti |
| Walstrom (n.d.) |
| Robert E.Walstrom Collection |
| Howard H. J. (2011) |
| DeVito (1992) |
| Yedlin (1964) |
| Watson (1902) |
| Kim Strange collection |
| Falster et al. (2019) |
| www.mindat.org (2007) +1 other reference |
| Jat Thompson Collection |
| Jat Thompson |
| - (2005) |
| Visual Id by Michael Cox |
| - (2005) |
| Walstrom (n.d.) |
| P. Cristofono collection (ex. Gene Bearss) |
| Thompson et al. (2022) |
| P. Cristofono collection |
| Steve Sorrell Collection |
| Pat R Gould Jr. Collection |
| Aidan Cerenzie Collection |
| Smith (1988) |
| Speer (1987) |
| Speer (1987) | |
| Speer (1987) | |
| Nassau et al. (1968) |
| Rockpick Legend |
| Michael Hatskel Collection |
| John Lindell field-collected specimens. |
| Frank Karasti |
Valeč Hyalite occurrences, Valeč, Karlovy Vary District, Karlovy Vary Region, Czech Republic