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GLASS

Miscellaneous

• Family: None
• Region: None
• Mined At: Unspecified
• Raw Mineral: Yes
• Generic: No

Notes

(Richard Willis)

Properly speaking, glasses, like glazes, are the cooled remains of once melted silicons (i.e., some form of silicon, as an oxide and/or in combination with other elements). Crystal rocks and minerals, though having a glass-like appearance, have been crystallized, not melted. In this sense, the only “natural” glass is obsidian. Crystals, such as beryl, have been used for special purpose 'glass' such as optics: as have other minerals, and are subsequently known as “mineral” o ptics rather than, say, “plastic” optics. Ceramic glaze is a ceramicist's glass. “Common” glass is synthetic and usually of silicon as its principal ingredient, as indicated by the following compositions.
common functional categories and their compositions (in a 1000º-2000ºC melting temperature range)
soda-lime silica — silica 70, soda 15, lime 10, magnesia 2.5, alumina 2.5
borosilicate — silica 60-80, boric acid 10-15, alumina 1-4
soft solder glass — silica 5, boric acid 15, lead oxide 64, zinc oxide 16
aluminosilicate — silica 5-60, alumina 20-40, lime 5-50, boric acid 0-10
light barium crown — silica 45-50, boric acid 3-5, soda 1, pot. ox. 7, barium. ox. 20-30, zinc ox. 10-15
dense barium crown — silica 30-40, boric acid 10-15, barium oxide 10-15, zinc oxide 0-10, alumina 0-10
extra dense flint — silica 20-40, potassium oxide 0-10, lead oxide 50-80
photosensitive — silica 72, soda 17, lime l 1, gold 0.02, selenium 0.04
photochromic — silica 60, soda 10, boric acid 20, alumina 10, iodine 0.9, silver 0.6, chlorine 0.3
high silica shrunken glass — silica 96, boric acid 3-4
infrared semi-conducting — arsenic 44, tellurium 24, iodine 32
anti-radiation (“common”) — silica 20, lead oxide 80

Authors

• Richard Willis (Owner)

XML

<?xml version="1.0" encoding="UTF-8"?>
<material name="GLASS" descrip="" generic="0" rawmineral="1" searchkey="" loi="0.00">
<notes>
<note>Properly speaking, glasses, like glazes, are the cooled remains of once melted silicons (i.e., some form of silicon, as an oxide and/or in combination with other elements). Crystal&lt;B&gt;&lt;I&gt; &lt;/I&gt;&lt;/B&gt;rocks and minerals, though having a glass-like appearance, have been crystallized, not melted. In this sense, the only &amp;#147;natural&amp;#148; glass is obsidian. Crystals, such as beryl, have been used for special purpose \'glass\' such as optics: as have other minerals, and are subsequently known as &amp;#147;mineral&amp;#148; o
ptics rather than, say, &amp;#147;plastic&amp;#148; optics. Ceramic glaze is a ceramicist\'s glass. &amp;#147;Common&amp;#148; glass is synthetic and usually of silicon as its principal ingredient, as indicated by the following compositions.&lt;BR&gt;
&lt;B&gt;common functional categories and their compositions &lt;/B&gt;(in a 1000&amp;ordm;-2000&amp;ordm;C melting temperature range)&lt;BR&gt;
soda-lime silica &amp;#151; silica 70, soda 15, lime 10, magnesia 2.5, alumina 2.5&lt;BR&gt;
borosilicate &amp;#151; silica 60-80, boric acid 10-15, alumina 1-4&lt;BR&gt;
soft solder glass &amp;#151; silica 5, boric acid 15, lead oxide 64, zinc oxide 16&lt;BR&gt;
aluminosilicate &amp;#151; silica 5-60, alumina 20-40, lime 5-50, boric acid 0-10&lt;BR&gt;
light barium crown &amp;#151; silica 45-50, boric acid 3-5, soda 1, pot. ox. 7, barium. ox. 20-30, zinc ox. 10-15&lt;BR&gt;
dense barium crown &amp;#151; silica 30-40, boric acid 10-15, barium oxide 10-15, zinc oxide 0-10, alumina 0-10&lt;BR&gt;
extra dense flint &amp;#151; silica 20-40, potassium oxide 0-10, lead oxide 50-80&lt;BR&gt;
photosensitive &amp;#151; silica 72, soda 17, lime l 1, gold 0.02, selenium 0.04&lt;BR&gt;
photochromic &amp;#151; silica 60, soda 10, boric acid 20, alumina 10, iodine 0.9, silver 0.6, chlorine 0.3&lt;BR&gt;
high silica &lt;B&gt;&lt;I&gt;shrunken glass&lt;/I&gt;&lt;/B&gt; &amp;#151; silica 96, boric acid 3-4&lt;BR&gt;
infrared &lt;B&gt;&lt;I&gt;semi-conducting&lt;/I&gt;&lt;/B&gt; &amp;#151; arsenic 44, tellurium 24, iodine 32&lt;BR&gt;
anti-radiation (&amp;#147;common&amp;#148;) &amp;#151; silica 20, lead oxide 80&lt;BR&gt;

</note>
</notes>
</material>

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