All of us remember that in school it was fundamental
to learn the various phases of biological classification:
kingdom, phylum, class, order, family, genus and species.
All animals, vegetables… and minerals fit into
this order. Chemical composition and crystal structure
distinguish a particular mineral. These two characteristics
determine the species, which is labelled with a name
(diamond, gemstone..). A minor variation in either of
these properties results in formation of a different
mineralogical species with a distinct name. Species with
similar characteristics constitute a group. Stones belonging
to the same mineral species are often varied with respect
to what is known as their optical characteristics. These
include colour, transparency and optical phenomena. Differences
in these factors determine a crystal’s
variety. For example, rubies and sapphires are varieties
of corundum. Rubies are characterised by their red colour,
while sapphires are blue.
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Based on their origin, stones can be classified into
the following types.
Synthetic: laboratory reproductions of stones already
existing in nature, having the same physical, optical
and chemical characteristics as their natural counterparts
(specific weight, refraction index, etc.).
Artificial: stones that do not exist in nature.
Natural: further subdivided into organic (coral, amber,
ivory, pearls, etc.) and inorganic.
The term “imitation” is used to describe
any substance that has physical aspects similar to a
natural stone. Since the times of the ancient Egyptians,
imitations were used to copy coral, lapis lazuli and
turquoise. They can be made from natural substances or
substances created by man (glass and plastic). Plastic
is generally used to imitate organic substances such
as coral, pearls, amber, etc., while glass is used to
imitate all other stones.
In the world of jewellery, the pureness and authenticity
of natural stones has always been highly valued, while
synthetic and artificial versions have been rejected.
Today, the jewellery industry is in danger of falling
into temptation, seduced by the extreme precision of
synthetic stones and their ease of introduction into
production chains, as well as by their low cost.
The Rajola policy has always demonstrated a preference
for natural stones over any type of imitation.
Although the costs and difficulties involved in finding
natural stones constitute a considerable impediment, when
we think of a jewel we imagine it to be an object that
is precious for its intrinsic beauty, its artisan value
and even its value over time – a quality that synthetic
and artificial stones do not have! Every natural stone
is unique. While this may be considered a limitation |
