April
Diamond
The name diamond refers to its hardness (Greek-adamas, the
unconquerable).
There is nothing comparable to it in hardness.
Its cutting resistance is 140 times greater than that of ruby and sapphire,
the gemstones next in hardness after diamond.
However the hardness of a diamond is different in the individual crystal
directions.
This allows one to cut diamond with diamond and/or with diamond powder.
Because of the perfect cleavage, care must be taken
not to accidentally bang against an edge of a diamond, and also when setting it.
Its very strong luster sometimes enables the experienced eye to differentiate
between a diamond and its imitations.
Diamond is generally insensitive to chemical reactions.
High temperatures, on the other hand, can induce etchings on the facets.
Therefore special care must be taken during soldering.
In the last fifty years, its been recognized that there are various types of
diamonds with different characteristics.
Science differentiates between type Ia, Ib, Iia, and Iib.
This is of little importance to the trade, but does assist the cutter.
Due to the optical effects, the high hardness, and its rarity, the diamonds
considered the king of gemstones.
Its been used for adornment since ancient times.