The birthstone of October is an OPAL. It's considered lucky to wear an opal if you were born in this month.
For those who were born in the month of October the Opal is the traditional birthstone. The October birthstone poem reflects some of the properties with which the Opal is associated - hope, innocence and purity. The Traditional Metaphysical Properties for the October Birthstone Opal are happiness, faithfulness, loyalty and confidence. The healing properties of the October birthstone are reputed to be effective for health problems relating to the eyes and eye infections. The Opal is also used to enhance visualization, imagination, dreams and healing.
For more about the birthstone.
And "Combined with modern techniques of polishing, doublet opal produces similar effect of black or boulder opals at a mere fraction of the price. Doublet opal also has the added benefit of having genuine opal as the top visible and touchable layer, unlike triplet opals."
"In the Middle Ages, opal was considered a stone that could provide great luck because it was believed to possess all the virtues of each gemstone whose color was represented in the color spectrum of the opal. It was also said to confer the power of invisibility if wrapped in a fresh bay leaf and held in the hand."
The Opal is a gift also.
Opal Healing and Magic -
"Opal talisman boosts foresight. According to some legends Opal's wearer can telepathically influence other people - if not for his own profit."
You can also find other October birthstones - "here"
October is a very interesting time, when the gates of this world are open to spirit realms and other dimensions, as they say. The threshold of the spirit realm comes down and this is a time when people are more sensitive to magic and visualising entities or experiencing supernatural forces. I'm going by the general view here. I personally think this isn't the only time of year but during the Autumn season, October is filled with celebration and feasting of the dead, in honour of ancestors, in recognition of the psyche and psychic abilities. Halloween comes by the end of the month, when the season is nearing the darker period of the year and Winter gets closer. Halloween is followed by other rites and rituals of the dead (not to mention the dressing up!)
The "Opal Wolf" is the special October birthday person of the month of October, whether is is those born under Libra (23 September- 22 October) and Scorpio ( 23 October - 21 November).
October born Libra people are balanced but scatty.
October born Scorpio people are loyal but frosty.
(These are just my own observations of people I knew born under these starsigns. Also it's combined with reading materials. This is not an assumption on each individual.)