Birthstones by Star Sign

Garnet - used as a gemstone since the Bronze Age
Colour - Red, Pink, Green, Orange, Yellow, Brown, Black
Properties -  Inspires love, energising, stimulates the metabolism

Amethyst used as a gemstone by the ancient Egyptians
Colour - purple to lavender
Properties  -  calms or stimulates the mind , enhance the memory, brings restful sleep

Bloodstone -  became popular for early Christians to wear  following the legend that it was created when drops of Christ's blood fell on a piece of green jasper at the foot of the cross.
Colour  - green with red flecks
Properties -cleanses the blood, reduces irritability, re- energises the body

Rose Quartz - believed to have been used as a gemstone by the Romans and Assyrians
Colour - soft pink
Properties - the love stone, calming, soothes burns

Agate - used by the Ancient Greeks
Colour -  milky white, blue, green and often artificially coloured
Properties - harmonises yin and yang, improves concentration, eliminates negative energies

Emerald - Cleopatra was enchanted by the emerald gemstone
Colour - Green
Properties - enhances unconditional love, said to foretell the future, soothes the eyes

Onyx - worn for centuries but particularly popular during the Art Deco Period
Colour - black, grey, white, blue brown, yellow, red
Properties - promotes stamina, conveys the gift of wise decision making, beneficial for bones

Carnelian - prized in India and Tibet and according to the Egyptian Book of the Dead it provides magic armour for the afterlife when placed in the tomb. 
Colour - red, orange, pink, brown
Properties -anchors you in the present, clarifies perception, heals lower back problems

Lapis Lazuli - prized by the Ancient Egyptians
Colour - dark blue with golden flecks
Properties - enhances dream work, encourages self-enlightenment,  alleviates pain

Citrine - used by the ancient Romans
Colour - yellow to yellowish brown
Properties - carries the power of the sun, energises every level of life, stimulates digestion

Topaz - used as a talisman by the Romans
Colour - blue, yellow, brown, clear
Properties - re-motivates, stone of good fortune, stimulates the metabolism

Ruby - worn by royalty and aristocrats around the world for centuries
Colour - red
Properties - protects from misfortune, sharpens the mind

Images of amethyst, emerald, onyx, ruby: courtesy of Boykung at Freedigitalphotos.net
Image of garnet: courtesy of: CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=426044
Image of bloodstone: By Ra'ike (see also: de:Benutzer:Ra'ike) - Own work, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=2372925
Image of carnelian: By Benjamint444 - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4316381
Image of citrine: CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=424222