Amethyst is associated with the Pisces sign, ruled by Neptune. This sign, being very sensitive, needs Amethyst for protection, steadiness and to banish melancholy.

Amethyst is the most precious stone of the quartz group. It comes from the greek "améthystos" and means anti-inebrating and it's said to have supernatural powers. This quartz is also rich in traditions ( in the Roman Church bishops usually wear a big Amethyst in the episcopal ring ).

Only the calcareous branching of Coral is used in jewellery. It forms by the action of small polyps scattered in the tiny cavities of the soft pellicle which covers the calcareous ramification. The most precious is the Noble Coral "corallium rubrum".

Coral is associated with the Aries sign, ruled by Mars. This stone gives the sign strength and energy.

Pearl is always associated with the Canger sign, ruled by Moon. It prefers all white and milky stones. Pearl is said to soften, calm and bring balance.

The name Pearl comes probably from a kind of shellfish called from the latin "perna". Pearl is produced by shellfish, made of mother of pearl, which is mainly calcium carbonate and organic substance, the ligand among the microcrystalls which develop in concentric circles starting from a little central area.

Tormalines present a wide range of colours, larger than any other gem. They are classified according to their colour and it's difficult to find one with a uniform colour. Originally they were called with a singhalese name "turamali".

Probably because of the extreme variety of their colous, I couldn't find any association with a zodiacal sign.

Lapis lazuli also hasn't got a particular position within the zodiac but can be associated to all those signs which prefer the blue colour.

Lapis lazuli comes from the medieval latin "lapis làzuli" which means blu stone. Many scientists don't consider it a mineral, but a rock. The colour is uniform in the best quality, but generally is spotted or streaky.

The name Jade comes from the spanish "piedra de la ijada" which means stone of the loins because it was used for renal diases in Central and South America. It's distinguished into two minerals: Jadeite and Nephrite. It comes in different colours. As for the first one, the most precious is the Imperial Jade, emerald green in colour, the second one is Green.

As for Jade I coudn't find a specific position in the zodiac because of its many colours.