Most jewelers learn pricing on gold, findings, and diamonds, then apply the same arithmetic to colored stones and wonder why the margins feel wrong. Sapphire and ruby behave differently: supply is inconsistent, comparables are hard to find, and the customer cannot price-check your stone against a rapaport sheet. This article covers how to build a markup structure for corundum that reflects what the stone actually costs you and what it will cost you to replace.
Why Colored Stones Don't Follow Diamond Pricing Logic
Diamond pricing is anchored to a published wholesale benchmark. A retailer selling a 1.00ct G VS1 round knows roughly what a customer will find online, and prices accordingly — often at thin margin, treating the stone as a traffic driver rather than a profit centre.
Corundum has no equivalent benchmark. Two 2.00ct blue sapphires with identical lab reports can differ in wholesale cost by a factor of three based on saturation, extinction, window, and how the stone performs in mixed lighting. That opacity is frequently framed as a problem. For a retailer it is the opposite: it is the reason colored stone margins are structurally healthier than diamond margins, and why a well-bought sapphire can carry a jewelry case.
The practical consequence is that your markup cannot be a single number. It has to respond to what kind of stone you are holding.
Keystone, Triple Keystone, and What Actually Happens in Practice
Keystone — doubling wholesale cost — is the traditional jewelry baseline. In colored stones, the working range most independent retailers land on looks roughly like this:
- Calibrated and commercial goods (under roughly $500/ct): keystone to 2.2x. These stones are replaceable, comparable, and competitive. Margin comes from volume and from the finished piece, not the stone.
- Mid-grade individual stones: 2.2x to 2.8x. You are being paid for selection — for having looked at forty stones and kept three.
- Fine and unheated goods: 2.5x to 3x or beyond. Replacement cost is genuinely uncertain, holding periods are long, and the customer is buying rarity rather than specification.
Note that markup rises as the stone becomes less replaceable. That is not opportunism — it is inventory risk being priced correctly. A parcel of calibrated 5x3mm ovals will turn several times a year. A 4ct unheated Ceylon sapphire may sit for eighteen months, and when it sells you may not find its equal at the same cost again.
Landed Cost Is Not the Invoice Price
The single most common pricing error we see from newer buyers is marking up the invoice figure rather than the landed cost. Before you apply any multiplier, the stone's true cost base should include freight and insurance, import duty and VAT or sales tax where applicable, payment processing or wire fees, lab certification if you commissioned it, and any recutting or repolishing.
On a $900 stone, those additions can easily total $120 to $180. Marking up the invoice instead of the landed figure silently removes several points of gross margin on every piece, and the error compounds across an entire season's buying. Build the landed-cost calculation into your intake process so it happens once, at receipt, rather than being reconstructed at the point of sale.
Carrying cost matters too. A stone financed on a line of credit and held for a year has consumed real money. Fast-turning calibrated sapphires and calibrated rubies carry very differently from statement goods, which is another reason a single blanket markup misprices both ends of your inventory.
Pricing Around Rarity and Reorder Risk
Ask one question before setting a price: can I buy this stone again?
If the answer is yes — standard sizes, treated material, steady supply — price competitively and compete on service, setting quality, and turnaround. If the answer is no, or only at materially higher cost, your price needs to fund the replacement rather than the historical purchase. Unheated stones, strong padparadscha and color-change material, matched pairs, and anything above four or five carats in good color all sit in this second category, where supply has tightened consistently over the past decade.
Retailers who price unheated goods at their old landed cost are effectively subsidising customers out of future inventory. Browse current unheated sapphires against what you paid two years ago and the gap is usually instructive.
Building a Structure That Survives Negotiation
Colored stone customers negotiate more than diamond customers, largely because they sense the pricing is discretionary. Two things protect margin. First, document the stone — origin, treatment status, lab report, and why you selected it. A specific story is far harder to discount than a generic one. Second, build a deliberate concession band into the ticket rather than discounting from a number you needed to hold, and decide in advance what your floor is.
At Thai Gems we have manufactured and wholesaled corundum from Bangkok for over 70 years, and the retailers who sustain the strongest margins are consistently the ones buying on landed cost with a clear view of replacement risk — not the ones chasing the lowest invoice.
Explore our full range of sapphires and rubies at thaigems.com, or contact us for trade pricing, parcel availability, and custom cutting to your production specifications.