MINERALOGICAL AND CHEMICAL KEY to the Glossary.
| Oxygen. This is a pure gas, and the most universally diffused substance in nature. | |
| Silicon | These elements will combine permanently with the principal gases. |
| Carbon | |
| Boron | |
| Alumina | These elements, when dissolved in certain acids, yield a colourless solution. |
| Magnesia | |
| Sulphur | |
| Manganese | These elements, dissolved in acids, yield a coloured solution. |
| Iron | |
| Gold | |
| Delessite is a chloride of iron. | |
Silica comprises only 2 species:—1. Quartz; 2. Opal.
From Quartz, come
| Rock-crystal | which are “vitreous,” |
| Cairn-gorums | |
| Sand | |
| and | |
| Chalcedony | which are “concretions.” |
| Agate | |
| Onyx | |
| Carnelian | |
| Sard | |
| Bloodstone | |
| Jasper | |
| Flints | |
Opal is a “hydrate” of Silica, containing 7 per cent. of water.
- Precious, or “noble.”
- Iridescent.
- Common (colourless).
“Silicates.”
| Of Alumina | Feldspar. |
| Kaolin. | |
| Of do. with Glucina | Emerald. |
| Beryl | |
| Garnet | |
| Pyrope, or “precious garnet.” | |
| Of Magnesia | Chrysolite. |
| Meerschaum. | |
| Asbest. | |
| Of do. with Fluorine | Topaz. |
| Tourmaline. | |
| Of do. with Zircon | Jargoon, or “Hyacinth.” |
The colour of “emerald” is due to the oxide of chrome; that of “beryl” to the oxide of iron.
Carbon comprises only 2 species:—1. Diamond; 2. Graphite.
“Diamond” is a perfect crystallization, and is the hardest substance known.
“Graphite” (sometimes called “Black-lead”) is a carbonate of iron. The iron, however, enters in very small quantities, and is now supposed to be accidental. “Graphite” is a concretion, and is never met with in the form of crystals.
“Carburets.”
| Of Hydrogen | Bitumen. |
| Coal. |
Bituminized wood is Lignite, which, when very compact, is Jet.
“Amber” is a vegetable resin. It is obtained from rivers in Sicily, and from mines in Russia.
| “Carbonates” of Lime | Limestone. |
| Calc-spar. | |
| Chalk. |
The “marbles” of Paros and Carrara are crystalline Limestone: those of Siena are compact Limestone.
Alumina comprises 2 species:—1. Corundum; 2. Sapphire.
1. “Corundum” is a very hard crystal, the common type of all the Sapphires.
2. Oriental “Sapphires.” These embrace 6 kinds.
- The blue Sapphire.
- ” red or “Ruby.”
- ” green or Emerald.
- ” purple or Amethyst.
- ” golden or Topaz.
- ” sea-green or Aquamarine.
These are pure Alumina.
“Emery” is a coarse variety of Corundum.
“Aluminates.”
| Of Magnesia | Spinel ruby. |
| Balas do. | |
| A Phosphate of Alumina and Magnesia | Turquoise. |
The “Spinel” ruby is scarlet; the “Balas,” of a faint pink. The “Oriental” ruby alone has the “pigeon’s blood” hue.
Localities of sundry “Fossils.”
| (Name of Fossil.) | (Proper locality.) | |
|---|---|---|
| Echini | Galerites Albogalerus | Found in the Upper Chalk, and, occasionally, in the Greensand. |
| Ananchytes Ovatus | ||
| Cor Anguinum | ||
| Ammonite | The Lias. | |
| Alcyonite | The Chalk. | |
| Troglodyte | ||
| Choanite | ||
| Ventriculite | ||
| Ichthyolite | The Old Red Sandstone. | |
| Cray-fish | The Gault. | |
| Shark’s teeth | The Tertiary Strata. | |
Plate I.
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Plate II.
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Plate III.
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Plate IV.
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Plate V.
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Plate VI.
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Plate VII.
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