Most rough gemstones require cutting and polishing to unlock the colour and lustre for which they are known. This is the job of the lapidary. .
The earliest method of cutting gems was simply to polish the flat crystal faces developed by nature. This later gave way to the cabachon, a style of cut imparting a curved upper surface. This is a French term which itself was derived from the Latin cabo, meaning head. Still in use today, the cabachon cut is used for star or cat’s eye gems. The cabochon may be cut in a number of ways. Domes vary from low, almost flat surfaces, through high, steeply curved surfaces. Usually a medium to high dome is preferable. The symmetry of the top and bottom surfaces on cabachons, and also nicely bevelled edges are criterions for a good cut. In cutting star material, orientation is all important, for, if done improperly, the star will be off-centre or nonexistent.
Only in the second half of the second millennium did we have the development of the faceted cut. Faceting, which produce scintillation in addition to colour, came into vogue with a technical improvement due to appearance of grindstones.
Grindstone has permit to add some new facets to the natural ones. Faceting is a technique which requires a lot of experience. The shape, proportions and orientation of the stone being determinant for its final value.
Variety of beryl appreciated for its special deep ocean blue. It is one of the fine stones which made the reputation of Madagascar among the lovers of stones.
The most appreciated stone from the quartz group. Its colour, from dark purple to violet and lilac is intense. One says that amethyst has supernatural powers: it’s a talisman giving chance and strength, protecting against spells and drunkenness.
Known for its various intense colours from green to turquoise blue and pale yellow. One of its varieties is scarce: the apatite «cat’s eye«, with a brilliant reflection slipping at the top of cabochon – cut apatites.
with its infinity of green shades, pale green, blue-green, etc.
Is a lemon yellow coloured quartz. Citrine is scarce, and the deposits of Madagascar are famous all over the world. A variety called «imperial« has a very beautiful orange-yellow colour.
A pyroxene with a green colour similar to the emerald one..
The most precious stone of the Beryl group. Its colour is a deep green, and the so-called "frost" inclusions form "the garden" of the emerald.
A sun’s gift is a pure yellow to golden yellow beryl.
Iolite or Cordiérite
Very beautiful fine stone, of a dark blue colour lightly purplish.
Very scarce fine stone with an intense dark green colour.
Variety of pink «peach tree flower» beryl, from pale pink to orange pink..
Meaning « eye of fire » in Greek, is a deep red garnet. Its colour looks similar to the ruby’s one. Rhodolite is a pinkish red variety of pyrope.
Madagascar is famous for its top quality rose quartz, the best in the world. One of its varieties showing a six rays star on the top of cabochon-cut stone.
Red corundum variety. The colour of ruby is one of those magnificent accidents of nature, the more searched one being the pigeon’s-blood red. Asteria or star stones are among the most marvellous of all corundums. The beautiful reflection of light, in the form of a star with six rays is given by cutting cabochons.
The term «sapphire» descended from the Greek meaning blue, includes all the varieties of corundum which aren’t red. For blue sapphire, the colour should be a rich blue, verging on the violet. The other colours are specified by the adjective attributed to the word sapphire: green sapphire, yellow sapphire. One of the delights of the corundum family is the lovely and very rare pinkish orange padparadscha meaning "lotus flower" in Sri Lanka.
An orange coloured garnet.
It’s a fine stone with a diamond brilliance, a very intense light in colours ranging from yellow, brown green, to apple green.
No gem offers a so rich colour range. Tourmalines are classified in different varieties according to their different colours. Rubellite is a raspberry pink to red tourmaline, Verdelite is the green one.