The metal associated with Thursday is tin, which is linked to Jupiter and the element Air. The energy is projective and pulls in good luck and prosperity.
Some stones & crystals associated with Thursdays are:
Amethyst- Amethyst is a type of quartz and comes in several shades, from a pinkish lavender to a deep purple with reddish tones. This stone corresponds to both Jupiter and Neptune, and is associated with the element of water. It is thought to be a spiritual stone and bring peace. Some believe that it corresponds to Spirit as well, and also the crown chakra. Amethysts can enhance precognitive dreams and strengthen intuitive skills. This stone is great for relieving stress when carried or worn, and I personally like to use it to help me sleep and relieve headaches by holding it while I fall asleep or holding it to my head to ease the headache.
Sapphire- This stone also falls into alignment with the energies of Thursdays because it's known for prosperity and money spells. These stones are also protective, and can be used for healing magick.
Turquoise- This stone is associated with the element Earth and is used to promote prosperity, ensure wealth, and it increases intuitive abilities/empathic qualities. It is a symbol of love and friendship, and is a luck, money and healing drawing stone which guards against danger and illness. In lore, if the stone breaks it's a sign to keep your eyes open for possible risk. Turquoise also promotes courage.