OBSIDIAN
Miscellaneous
- Family: None
- Region: None
- Mined At: Unspecified
- Raw Mineral: Yes
- Generic: No
Notes
(Richard Willis)
Volcanic rock, essentially of vitrified rocks rich in silica and alkalis along with substantial traces of cristobalite and magnetite. Formed by rapid cooling of magma emissions rich in silicon. Known as “Nature’s glass” and “natural glass”, it is also referred to as “volcanic glass” and “granite-glaze” (in the sense that when granite is melted, as when to be used as a glaze, it is similar to obsidian in appearance; and one imagines that prior to melting obsidian
would have likewise resembled the alkali-rich variety of granite). Usable in both clays and glazes as a substitute for or supplement to a fritted base of silica + alkalis, and especially where a reinforcement by cristobalite is desirable.
Authors
- Richard Willis (Owner)
Pictures
-
Cristobalite In Obsidian
-
Obsidian Black Rainbow
-
Obsidian Cristalline
-
Obsidian Cut Pol
-
Obsidian Mahogany
-
Obsidian Sphere
-
Obsidian Violet Green
XML
<?xml version="1.0" encoding="UTF-8"?>
<material name="OBSIDIAN" descrip="" generic="0" rawmineral="1" searchkey="" loi="0.00">
<notes>
<note>Volcanic rock, essentially of vitrified rocks rich in silica and alkalis along with substantial traces of cristobalite and magnetite. Formed by rapid cooling of magma emissions rich in silicon. Known as &#147;Nature&#146;s glass&#148; and &#147;natural glass&#148;, it is also referred to as &#147;volcanic glass&#148; and &#147;granite-glaze&#148; (in the sense that when granite is melted, as when to be used as a glaze, it is similar to obsidian in appearance; and one imagines that prior to melting obsidian
would have likewise resembled the alkali-rich variety of granite). Usable in both clays and glazes as a substitute for or supplement to a fritted base of silica + alkalis, and especially where a reinforcement by cristobalite is desirable.
</note>
</notes>
<pictures>
<picture description="Cristobalite In Obsidian" filename="cristobalite_in_obsidian.jpg"/>
<picture description="Obsidian Black Rainbow" filename="obsidian_black_rainbow.jpg"/>
<picture description="Obsidian Cristalline" filename="obsidian_cristalline.jpg"/>
<picture description="Obsidian Cut Pol" filename="obsidian_cut_pol.jpg"/>
<picture description="Obsidian Mahogany" filename="obsidian_mahogany.jpg"/>
<picture description="Obsidian Sphere" filename="obsidian_sphere.jpg"/>
<picture description="Obsidian Violet Green" filename="obsidian_violet_green.jpg"/>
</pictures>
</material>
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