To make a stone material ideal for tool production, it must be non-crystalline or glassy, which allows for conchoidal fracturing.
32.
Like all glass and some other types of naturally occurring rocks, obsidian breaks with a characteristic conchoidal fracture, creating razor sharp edges.
33.
Blows that result in deep conchoidal fractures ( the first phase of manufacture ) can be distinguished from features resulting from sharpening with a soft hammer.
34.
Also, it possesses dual quality of translucent to cleavage and distinct rhombohedral cleavage with hackly fracture, on the other side spherulitic grains are conchoidal.
35.
In amorphous solids, by contrast, the lack of a crystalline structure results in a conchoidal fracture, with cracks proceeding normal to the applied tension.
36.
Sepiolite is opaque and off-white, grey or cream color, breaking with a conchoidal or fine earthy fracture, and occasionally fibrous in texture.
37.
In most cases, the amount of pressure applied to the objective piece in soft-hammer percussion is not enough for the formation of a typical conchoidal fracture.
38.
Lead-grey in colour ( frequently displaying an iridescent tarnish ), its Mohs scale, has a density of approximately 6.4, and a conchoidal fracture.
39.
Prominent bulbs of force generally indicate that a hard hammer percussor ( hammerstone ) was used to detach the flake; flakes displaying this characteristic are referred to as conchoidal flakes.
40.
It is important to note that blade cores appear and are different from regular flaking cores, as each core's conchoidal nature is suited for different types of flaking.
