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| | Agate |
 | | When the deposits in an agate have been formed on a crop of crystals, or on a rugose base, the cross-section presents a zigzag pattern, rather like the plan of a fortress with salient and retiring angles, whence the stone is termed fortification agate. |
 | | A Mexican agate, showing only a single eye, has received the name of "cyclops." Included matter of a green colour, like fragments of "green earth," embedded in the chalcedony and disposed in filaments and other forms suggestive of vegetable growth, gives rise to moss agate. |
 | | An enormous trade in agate-working is carried on in a small district in Germany, around Oberstein on the Nahe, a tributary of the Rhine at Bingen. |
| www.jewelry-paideia.com /reference/ref-gemstone-agate-1.php (1967 words) |
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