Navigating the Complex World of High-Value Materials

Accurately converting between units of weight, purity, and value for precious metals and gemstones is critical for investors, jewelers, appraisers, and collectors. Unlike standard conversions, these calculations involve troy ounces, karat purity, and real-time market prices. This guide serves as your authoritative Precious Metals & Gems Converter, providing the formulas, charts, and knowledge needed to make informed decisions, whether you're calculating melt value, comparing gem weights, or planning a jewelry piece.

Important Note: A "precious metals & gems converter contact number" does not exist for a universal tool. Conversions require current market data and expertise. Always verify calculations with a certified appraiser or reputable dealer for high-value transactions.

Part 1: Precious Metals Weight & Purity Conversion

The Troy Weight System

Precious metals are weighed in troy ounces (oz t), not the standard avoirdupois ounces used for common weight.

1 Troy Ounce (oz t) = 31.1034768 Grams (g)
1 Avoirdupois Ounce = 28.3495 grams
1 Kilogram = 32.1507 Troy Ounces

A standard metal conversion calculator often defaults to avoirdupois ounces, which will give incorrect results. Ensure you are using a tool designed for precious metals.

Gold Purity: Karats vs. Millesimal Fineness

24 Karat (24K) = 99.9% pure gold (999 fineness)
18 Karat (18K) = 75.0% pure gold (750 fineness)
14 Karat (14K) = 58.3% pure gold (583 fineness)
10 Karat (10K) = 41.7% pure gold (417 fineness)

Formula to find pure gold content:
Pure Gold Weight = Total Item Weight × (Karat Value / 24)

Gold Weight Conversion Chart (Troy Ounces)

Troy Ounces (oz t)Grams (g)Grains (gr)0.1 oz t3.11 g48.0 gr1 oz t31.10 g480 gr5 oz t155.52 g2,400 gr10 oz t311.03 g4,800 gr

Part 2: Critical Metal-to-Metal Conversion Explanations

1. Silver to Gold Conversion Calculator (Value-Based)

You cannot convert silver weight directly to gold weight. Conversion is based on current market value.

Example Value Conversion:

Check live prices: e.g., Silver = $28/oz t, Gold = $2,300/oz t.
Gold-to-Silver Ratio = $2,300 / $28 ≈ 82:1.
1 oz t of Gold is worth approximately 82 oz t of Silver at this ratio.

A true silver to gold weight conversion calculator is a value equivalency tool, not a physical weight converter.

2. 14K Gold to Platinum Conversion (Conceptual)

Similar to above, this is not a direct weight or purity conversion. It’s a value and density comparison:

Value: Compare the market price of the amount of pure gold in your 14K item to the equivalent value of pure platinum.
Casting (Jewelry): If substituting metals in a mold, you must account for density. Platinum (~21.45 g/cm³) is denser than gold (~19.32 g/cm³). A wax model that yields 10 grams of 14K gold will yield approximately 11.1 grams of pure platinum.

3. Brass to Gold Weight Conversion (A Common Misconception)

Brass and gold have different densities. A weight conversion is only physical, not valuative.

Density of Yellow Brass: ~8.4 g/cm³
Density of 14K Gold: ~13.6 g/cm³
A 1 cm³ volume of brass weighs about 8.4g. The same volume of 14K gold weighs about 13.6g.

This is relevant for lost-wax casting where a wax pattern's volume is replaced by metal. There is no meaningful "conversion" for value.

Part 3: Jewelry-Making & Casting Specifics

Wax to Gold Conversion Chart (For Lost-Wax Casting)

This critical step estimates the final metal weight from a wax model. It uses the metal's density versus wax's density.

General Multiplier Rule of Thumb:

For Gold (14K-18K): Final metal weight is typically 14–16 times the weight of the wax model.
For Silver: Final metal weight is typically 12–14 times the weight of the wax.
For Platinum: Final metal weight is typically 17–19 times the weight of the wax.

Important: This is an estimate. The exact multiplier depends on the specific wax density and alloy. Professional casters use precise calculations:
Metal Weight = Wax Volume (cm³) × Metal Density (g/cm³) × (1 + Casting Allowance %)

Part 4: Gemstone Weight Conversion

Gemstones are weighed in carats (ct), where 1 carat = 0.2 grams = 200 milligrams.

1 carat = 100 points (a 0.50 ct stone is 50 points)
5 carats = 1 gram

Warning: Carat (ct) for gem weight is different from Karat (K or kt) for gold purity.

Part 5: How to Use a Precious Metals Converter: A Step-by-Step Guide

Identify Your Goal: Are you converting weight units (t oz to grams), calculating pure metal content, or finding value equivalence?
Gather Data: You will need the item's total weight (in troy ounces or grams) and its purity (karat or fineness). For value, you need live spot prices.
Select the Correct Tool/Formula:
- For weight: Use the troy ounce conversion formulas.
- For purity: Use the karat formula.
- For value: Use live price feeds from Kitco, LBMA, or APMEX.
Double-Check with a Chart: Verify your math against a gold weight conversion chart.
Consult a Professional: For items of significant value, final calculations should be confirmed by an expert.

FAQs on Precious Metals & Gems Conversion

Where can I get a reliable live conversion or appraisal?

Reputable sources include:

For Live Prices: Kitco, JM Bullion, APMEX.
For Appraisals: A Certified Member of the American Society of Appraisers (ASA) or the National Association of Jewelry Appraisers (NAJA).
Do not rely on a generic "contact number"—seek established businesses with verifiable credentials.

Is a 1-gram gold bar the same as 1 gram of jewelry?

No. A 1-gram gold bar is typically 99.99% pure. A 1-gram piece of 14K jewelry contains only 0.583 grams of pure gold; the rest is alloy. Value differs significantly.

How do I calculate the melt value of my scrap gold?

Weigh it in grams.
Convert to troy ounces: Troy Ounces = Grams / 31.1035.
Determine purity (e.g., 14K = 0.583 fine).
Multiply: (Weight in oz t) × (Purity) × (Current Gold Spot Price per oz t).

Why is platinum more valuable than gold but sometimes priced lower?

Value is not solely determined by price per ounce. Platinum is denser, so an identical ring will weigh more than a gold one. Market dynamics (industrial demand, investment flows) also cause price fluctuations where platinum can trade at a discount to gold.

Conclusion: Convert with Knowledge and Caution

Mastering conversions for precious metals and gems requires understanding three separate domains: weight systems (Troy vs. Avoirdupois), purity standards, and volatile market values. Use the formulas and charts here—like the wax to gold conversion chart for casting or the gold weight conversion chart for investing—as your foundational tools.

Final Critical Advice: For any transaction involving substantial value, use your calculations as an initial guide, but always seek a second opinion from a trusted, certified professional. The cost of an appraisal is minor compared to the risk of a significant miscalculation.

Disclaimer: This guide is for educational and informational purposes only. The conversions, especially value-based ones, are highly time-sensitive and dependent on live market data. The authors are not financial advisors, gemologists, or certified appraisers. Alloy densities and casting multipliers are approximations. For buying, selling, insuring, or creating jewelry, consult with qualified professionals. Prices of precious metals and gems are volatile and past performance is not indicative of future results.