-
Metals Used to Color Glass
The recipe for producing colored glass usually involves the addition of a metal to the glass. This is often accomplished by adding some powdered oxide, sulfide, or other compound of that metal to the glass while it is molten. The table below lists some of the coloring agents of glass and the colors that they…
-
Colors of Duration
Then, another problem was discovered. Many of the glass colors did not stand up to year-in, year-out exposure to the direct rays of the sun. The result was a stained glass scene of deteriorating beauty. Some colors darkened or changed over time, while others faded away. Red, a very important color for use in a…
-
The Glass Color Palette
Once the methods of colored glass production were discovered, an explosion of experimentation began. The goal was to find substances that would produce specific colors in the glass. Some of the earliest objects made from glass were small cups, bottles, and ornaments. Religious organizations were among those who provided incentive to the early glass artisans.…
-
The Colored Glass Recipe
The earliest people who worked with glass had no control over its color. Then, through accident and experimentation, glass makers learned that adding certain substances to the glass melt would produce spectacular colors in the finished product. Other substances were discovered that, when added to the melt, would remove color from the finished project. Egyptian…
-
Color: The Most Obvious Property of Glass
Color is the most obvious property of a glass object. It can also be one of the most interesting and beautiful properties. Color sometimes defines the usefulness of a glass object, but it almost always defines its desirability.
-
Monoclinic and Orthorhombic Pyroxene
Pyroxene minerals crystallize in both the monoclinic and orthorhombic crystal systems. Monoclinic pyroxenes are known as “clinopyroxenes” and orthorhombic pyroxenes are known as “orthopyroxenes”. Pyroxenes can also be classified on the basis of their chemical composition. The classes include: magnesium-iron pyroxenes, calcium pyroxenes, calcium-sodium pyroxenes, sodium pyroxenes, and lithium pyroxenes. Two lists of pyroxene minerals…
-
Extraterrestrial Occurrence of Pyroxenes
Pyroxene minerals are known beyond Earth. They are abundant in many stone meteorites and present in some stony-iron meteorites. They have also been identified in the rocks and regolith of the Moon and Mars. When compared to terrestrial rocks, rocks of the Moon and Mars have simple mineral compositions. This is because they have not been significantly altered by…
-
Geologic Occurrence of Pyroxenes
In Earth’s crust, pyroxenes are found in a wide range of igneous and metamorphic rocks. They are most abundant in the dark-colored igneous rocks, such as basalt and gabbro, that comprise most of the oceanic crust. Pyroxenes and plagioclase feldspar are the most abundand minerals in these rocks. Pyroxenes are also important minerals in many peridotites. Rocks of the upper mantle…
-
Construction Materials
Pyroxene minerals are primary or secondary constituents of many rocks used to make crushed stone, dimension stone, and architectural stone. Pyroxene is in the trap rock of the construction industry and in the “black granites” that are popular for making decorative tile and facing stone.
-
Hypersthene and Enstatite
Rare specimens of hypersthene and enstatite sometimes display a colorful sheen known as “schiller”. Rare specimens of enstatite will display asterism in the form of four-ray or six-ray stars. These specimens of gem-quality enstatite and hypersthene are so rare that they are “collector’s stones” instead of gems frequently seen in jewlery.