On Dhanteras, two days before Diwali, families across India buy gold: a coin, a chain, a new steel vessel at the very least.
The Gītā has a phrase for the wise person, and it uses it twice, word for word. At 6.8 and again at 14.24: sama-loṣṭāśma-kāñcanaḥ. One to whom a clod of earth, a stone and a piece of gold are the same.
It is not a ban on gold. It is a test of who owns whom.
Buy the gold. Just don’t let it own you.
The verses
BHAGAVAD GĪTĀ · 6.8ज्ञानविज्ञानतृप्तात्मा कूटस्थो विजितेन्द्रियः।
युक्त इत्युच्यते योगी समलोष्टाश्मकाञ्चनः।।
jñāna-vijñāna-tṛptātmā kūṭa-stho vijitendriyaḥ
yukta ityucyate yogī sama-loṣṭāśma-kāñcanaḥ
The yogin whose mind is content with knowledge of the self and also with knowledge of the difference between the self and Prakrti, who is established in the self, whose senses are subdued, and to whom earth, stone, and gold all seem alike, is called integrated.
BHAGAVAD GĪTĀ · 14.24समदुःखसुखः स्वस्थः समलोष्टाश्मकाञ्चनः।तुल्यप्रियाप्रियो धीरस्तुल्यनिन्दात्मसंस्तुतिः।।
sama-duḥkha-sukhaḥ sva-sthaḥ sama-loṣṭāśma-kāñcanaḥ
tulya-priyāpriyo dhīras tulya-nindātma-sanstutiḥ
He who is alike in pleasure and pain, who dwells in his Self, who looks upon a clod, a stone, and a piece of gold as of equal value, who remains the same towards things dear and hateful, and who is intelligent, who regards both blame and praise of himself as equal.
Going deeper
Two verses in the Gītā describe the same person in nearly the same words. In chapter 6, 6.8 describes a yogi who is content with knowledge, steady in the self and master of the senses, and to whom a clod, a stone and gold look alike. The verse before it, 6.7, speaks of heat and cold, pleasure and pain, honour and dishonour, and the one after, 6.9, extends the same evenness to friends and enemies. The phrase returns in chapter 14. 14.24 describes the one who has risen above the three guṇas: the same in pleasure and pain, dwelling in the self, looking on earth, stone and gold alike, and treating praise and blame as equal. 14.25 closes the list with honour, dishonour, friend and foe. Nothing here forbids owning gold. The test is whether the gold changes the one who holds it. See chapter 6, chapter 14 and what the Gītā says about knowledge.