Gold Belongs to the Sun and Silver to the Moon

Gold is associated with the Sun and silver with the Moon. The Sun's gem in the same tradition is ruby, and the Moon's is pearl. Luck, bhagya, is the 9th house and its lord, with Jupiter as the karaka. If the 9th lord is Mercury, neither gold nor silver is the metal of the luck lord. Choosing a metal because a shop calls it lucky skips the 9th. Strengthen the Sun with gold only when the Sun's houses are worth strengthening. For a Leo lagna the Sun is the lagna lord, so solar strength is the person. For an Aquarius lagna the Sun rules the 7th, so gold talks to marriage, not automatically to luck.

Silver tracks Chandra. A Moon exalted in Taurus has less need of a boost than a Moon debilitated in Scorpio. The Moon rules the 4th for an Aries lagna, because Cancer is fourth from Aries, so silver in that chart speaks to home and the mind together. It still does not speak to the 9th unless the Moon rules the 9th, which it does for a Scorpio lagna. For a Cancer lagna the 4th is Libra, ruled by Venus, so silver is not the 4th-house metal there. One sentence of lordship replaces a universal ranking of metals.

Wearing gold and silver together to cover luck is wearing two grahas you may not need. If Saturn rules the 9th, as it does for Taurus, the luck lord is Saturn, whose metal in remedial custom is iron, and whose gem is blue sapphire, a serious choice because it strengthens a slow malefic. That is a different article and a different caution. For this question, identify the 9th lord, then see whether the Sun or the Moon even appears. If your Moon is weak and your question is peace rather than luck, silver matches the question you actually have. Call it the Moon's support. Do not call it better luck.