The price of a gram of 9-carat gold does not result from a specific quotation. It derives from a calculation applied to the price of pure gold, which is set twice a day on a centralized market. Understanding this mechanism requires going back to the source: the London fixing, the conversion to grams, and then the application of a purity coefficient of 37.5%. Each link in this chain introduces a variable that affects the final price.
From LBMA fixing to 9-carat gold per gram: the calculation chain
The starting point is the spot price of gold, determined by the London Bullion Market Association (LBMA). This fixing, established twice a day by matching supply and demand, provides a global reference price expressed in dollars per troy ounce.
To obtain a price per gram in euros, two conversions follow. The troy ounce is equivalent to approximately 31.1 grams: thus, the price is divided by this value. Then the result is converted from dollars to euros according to the current exchange rate.
A gram of 9-carat gold contains only 37.5% fine gold, which corresponds to the 375 thousandths standard. The final formula can be summarized as follows:
| Step | Operation |
|---|---|
| Spot price (ounce) | LBMA price in dollars |
| Conversion to grams | Spot price / 31.1 |
| Conversion to euros | Price per gram in USD x EUR/USD rate |
| Application of the 9-carat standard | Price per gram of pure gold x 0.375 |
This calculation gives the theoretical value of a gram of 9-carat gold, the one found on real-time quotation sites. You can find the price of a gram of gold on Réussir Investir to track this updated value.
Dollar-euro exchange rate and spot price: two variables that weigh equally
The price of gold is quoted in dollars. For a buyer or seller in the eurozone, the EUR/USD parity affects the price as much as a variation in the spot price. A dollar that strengthens against the euro mechanically increases the price of gold per gram in euros, even if the spot price in dollars remains stable.
This double exposure explains why the price of a gram of 9-carat gold in euros does not always follow the same trajectory as the spot price displayed in dollars. On days when the dollar appreciates significantly, the price in euros may rise while the ounce price falls in New York or London.
Conversely, when the euro strengthens, a European investor sees the price of the gram decrease in local currency, which can create buying opportunities that are not revealed by simply tracking the price in dollars.
Discrepancy between theoretical quotation and buyback price at the counter
The value calculated by the formula above remains a reference price. At the counter, the buyback price of a 9-carat gold piece always deviates from this, and not in favor of the seller.
Buyback professionals apply a margin that covers several items:
- Refining costs, since the jewelry must be melted down and the gold separated from other metals in the alloy before being resold as fine gold.
- Uncertainty about the actual purity, especially when the jewelry does not bear a visible hallmark, which is common for small 9-carat pieces like fine chains or earrings.
- The commercial margin of the counter, which varies according to local competition and the volume traded.
A 9-carat piece without a hallmark will incur a greater discount than a clearly hallmarked 375 piece. The professional cannot guarantee the purity without testing, and passes this risk onto the price offered.
375 hallmark and legal threshold in jewelry
The 375 thousandths standard constitutes the minimum threshold for an alloy to be legally sold as gold in several hallmarking systems, notably in the United Kingdom. This “entry threshold” status in jewelry has a direct consequence: buyback scales remain indexed to the price of fine gold, even for this very low standard.
The 9-carat does not fall into the category of non-precious metals, which keeps its buyback value above the simple value of the copper-silver-zinc alloy that makes up the remaining 62.5%.
Supply, demand, and geopolitical context: what moves the price of fine gold
The price of a gram of 9-carat gold being a direct derivative of the price of pure gold, anything that influences the latter mechanically affects the 9-carat.
Interest rates play a central role. Gold does not generate yield. When rates rise, bond investments become more attractive, and the price of gold tends to fall. The inverse relationship is observed during periods of falling rates.
Purchases by central banks also weigh on demand. When large central banks increase their gold reserves, they exert upward pressure on the spot price, which pulls the price of all alloys up, including 9-carat.
Geopolitical tensions and financial crises push investors toward gold as a safe haven. These spikes in demand can cause the price to fluctuate by several percent in a few days, resulting in visible fluctuations in the buyback price of 9-carat jewelry on a daily basis.
Real-time quotation and retail price in jewelry: two distinct realities
The price displayed on a quotation site reflects the metal value of a gram of 9-carat gold at a given moment. The retail price of a new 9-carat piece in a store incorporates costs that have nothing to do with the spot price.
Manufacturing, design, brand, and retailer margin can multiply the price by two or more compared to just the value of the contained gold. A 9-carat gold bracelet sold in a jewelry store costs much more than the weight of gold it contains, valued at the current price.
Conversely, in buyback, only the metal counts. The jeweler’s craftsmanship has no value at the time of resale for melting. This asymmetry between the purchase price in-store and the buyback price at the counter often surprises individuals who expect to recover a significant portion of the initial price.
The price of a gram of 9-carat gold is summarized as a fraction, 37.5%, applied to a globally quoted price in dollars and converted to euros. The most underestimated variable remains the exchange rate, which can amplify or dampen movements in the spot price depending on when one buys or sells.