Crossword-Solution: BOART 5 letters, 5 clues 🏆 scrabble score: 7

Bort (or Boart) is the name given to impure crystals or fragments useless for jewels; it is also applied to the rounded crystalline aggregates, which generally have a grey colour, a rough surface, often a radial structure, and are devoid of good cleavage.

But most of the talk is of the precious stones themselves and the mines in which they are found--of falls of reef in Kimberley, and of the price of glassy stones, cape whites, off-coloured stuff, and boart.

The "boart" should therefore be grasped by the thumb and first finger, and the wire wound round; then it must be carefully turned and again wound across with the platinum wire, as in the sketch below.

The fragment of "boart" or refuse diamond.] A piece of black lead (so called) may now be taken from a lead pencil and also supported by platinum wire; likewise a bit of common bark charcoal or hard coke.

The fragment of diamond is by no means, however, so [Page 154] easily ignited, the flame of the spirit lamp must be urged upon it with the blowpipe; when quite red hot, an assistant may remove the stopper from the bottle of oxygen, and the person heating the diamond should plunge it instantly into the gas; if this is dexterously managed, the fragment of _boart_ glows like a little star, and the combustion frequently continues till the piece diminishes so much that it falls out of its platinum support.