Mabé
: a half pearl obtained from a nucleus inserted under the mantle of a nacre.
(Exports in 1994 : 24.2 kilos valued at one million French francs). Surgreffe : An operation consisting of harvesting a black pearl produced by a nacre after a first greffe. Immediately after, one introduces another and larger nucleus than the first, thus pushing the nacre to produce a second pearl of larger diameter.
Naissain
: Swimming larvae of bivalves (oysters, nacres, mussels) prior to their
attachment. By extension, the name naissain also designates the very small
nacres attached themselves to a support. Aragonite : A carbonate of calcium, Ca Co3, it is an intégral part of the shells of aquatic molluscs and the essential component of the pearl.
Collecteur : Artificial furnishing of tree trunks, miki miki branches, latrices, metal fencing, etc... to the free swimming larvae of the nacres, as points of attachment.
Nucleus or noyau : A tiny pearl grown in the shell od a bivalve living in the Mississipi River. It is the "foreign body" introduced into the nacre, with the greffon at the moment of grafting.
Greffon : It is a tiny fragment of the mantle of a nacre that is slipped into the gonad of the nacre being grafted, at the same time as the nucleus.
Manteau
(mantle) : found in all molluscs, it is a fold of flesh covering and
protecting the viscera of the animal and secretes the shell without adhering
to it. Keshi : In a sense, an unsuccessful black pearl, as it happens that the grafted nacre rejects the nucleus, retaining in the gonad only the little greffon. Lacking a clearly defined shape, it nonetheless manages to stimulate the production of aragonite. As a result, the nacre produces a natural black pearl with a highly irregular form and without a nucleus. (Exports in 1995 : 57 kilos valued at 5.3 million french francs)
Greffe : Operation performed by human hand consisting of introducing a nucleus and a greffon into the poche perliere of a nacre, in order to have it produce a pearl. A good grafter can perform this operation around 300 times per day.
Conchyoline : Organic matter found in small quantity in a pearl (around 5 %), serving as a supporting screen for the aragonite.
Poche perliere : n appendage into which are introduced the nucleus and the greffon during the grafting.
Orient : This is the play of light on a pearl. It can vary according to the manner in which the coats of aragonite are deposited on the nucleus of the pearl. Certain pearls have a weak orient, tending to have a matte surface. Others have a very deep orient, as the light seems to play in the depths of the nacreous layers of the pearl.
Lustre : It designates the brilliance - on the surface - of a pearl placed under a direct light. this is not to be confused with orient, the pearl's inner glow.
Blister : Found on the inner surface of some nacre shells, it is often the result of the nacre having trapped a foreign body between the shell and the mantle. the aragonite of the shell's inner surface becomes blistered by the decomposition of the imprisoned organic body.
|