It is transparent like white sugar-candy; they swallow the small crystalline particles which crumble off as a preventative of sickness.

It scratches glass, and does not effervesce with acids.

From another specimen the stone appears to be agate of a milky hue, semi-pellucid, and strikes fire.

The vein from which it appears broken off is one inch and a quarter thick.

A third specimen contains a portion of cornelian, partially crystallized, a fragment of chalcedony, and a fragment of a crystal of white quartz.
...
And again in Mitchell's Expeditions into Australia, volume 2 page 338: In these girdles the men, and especially their coradjes or priests, frequently carry crystals of quartz or other shining stones, which they hold in high estimation, and very unwillingly show to anyone; invariably taking care, when they do unfold them, that no woman shall see them.
...
FORMS ON MAKING VOWS AND PLEDGES.
Genesis chapter 24 verse 9.