Difference between revisions of "Light opal"
Jump to navigation
Jump to search
(username removed) |
|||
| (2 intermediate revisions by 2 users not shown) | |||
| Line 1: | Line 1: | ||
== Description == | == Description == | ||
| − | An [ | + | An [[opal]] with pale iridescent colors. Light opals typically have bluish or greenish tones but may also show oranges and pinks. The colors depend on the crystal size within the stone. When the particles are small, some purple can be seen. Medium sized particles diffract green and larger particles show red. Light opals with an opaque, milky background are called white or milk opals. Most light opals come from Australia (Coober Pedy and Mintabie mines). |
== Synonyms and Related Terms == | == Synonyms and Related Terms == | ||
| Line 7: | Line 7: | ||
white opal; milk opal | white opal; milk opal | ||
| − | == | + | ==Physical and Chemical Properties== |
| − | Massive with no crystalline structure. Cleavage=none Luster = vitreous to pearly. Fracture = conchoidal. Streak = white | + | * Massive with no crystalline structure. |
| − | + | * Cleavage=none | |
| − | Iridescent. | + | * Luster = vitreous to pearly. |
| + | * Fracture = conchoidal. | ||
| + | * Streak = white | ||
| + | * Iridescent. | ||
| + | * Fluorescence = usually white or pale green, some samples phosphoresce | ||
{| class="wikitable" | {| class="wikitable" | ||
| Line 19: | Line 23: | ||
|- | |- | ||
! scope="row"| Density | ! scope="row"| Density | ||
| − | | 2.15 | + | | 2.15 g/ml |
|- | |- | ||
! scope="row"| Refractive Index | ! scope="row"| Refractive Index | ||
| Line 25: | Line 29: | ||
|} | |} | ||
| − | == | + | ==Resources and Citations== |
* ''Van Nostrand's Scientific Encyclopedia'', Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976 | * ''Van Nostrand's Scientific Encyclopedia'', Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976 | ||
| − | * Wikipedia | + | * Wikipedia: http://en.wikipedia.org/wiki/Opal (Accessed Oct. 12, 2005) |
* Yasukazu Suwa, ''Gemstones: Quality and Value, Volume 1'', Sekai Bunka Publishing Inc., Tokyo, 1999 | * Yasukazu Suwa, ''Gemstones: Quality and Value, Volume 1'', Sekai Bunka Publishing Inc., Tokyo, 1999 | ||
Latest revision as of 13:06, 7 October 2022
Description
An Opal with pale iridescent colors. Light opals typically have bluish or greenish tones but may also show oranges and pinks. The colors depend on the crystal size within the stone. When the particles are small, some purple can be seen. Medium sized particles diffract green and larger particles show red. Light opals with an opaque, milky background are called white or milk opals. Most light opals come from Australia (Coober Pedy and Mintabie mines).
Synonyms and Related Terms
white opal; milk opal
Physical and Chemical Properties
- Massive with no crystalline structure.
- Cleavage=none
- Luster = vitreous to pearly.
- Fracture = conchoidal.
- Streak = white
- Iridescent.
- Fluorescence = usually white or pale green, some samples phosphoresce
| Mohs Hardness | 5.5-6.5 |
|---|---|
| Density | 2.15 g/ml |
| Refractive Index | 1.42-1.47 |
Resources and Citations
- Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
- Wikipedia: http://en.wikipedia.org/wiki/Opal (Accessed Oct. 12, 2005)
- Yasukazu Suwa, Gemstones: Quality and Value, Volume 1, Sekai Bunka Publishing Inc., Tokyo, 1999
- Michael O'Donoghue and Louise Joyner, Identification of Gemstones, Butterworth-Heinemann, Oxford, 2003