A hard, dark-colored glassy phase of lava.
A stone profile with a reverse curved edge: concave above, convex below.
A dense, crystalline form of lime carbonate deposited usually from cold-water solutions. Generally translucent and shows a characteristic layering due to mode of accumulation.
A calcite-cemented calcareous stone formed of shells and shell fragments, practically non-crystalline in character. It is found in massive deposits located almost entirely in Lawrence, Monroe and Owen Counties, Indiana and in Alabama, Kansas and Texas. This limestone is characteristically a freestone, without cleavage planes, possessing a remarkable uniformity of composition, texture and structure. It possesses a high internal elasticity, adapting itself without damage to extreme temperature changes.
The introduction into a rock of siliceous material in the form of opal, a hydrous silicate.
|Out of Wind||
To have the arris or edge of an external angle of a stone not in parallel or perpendicular lines. Stone which is out of wind has an irregular or rustic appearance