The laboratory does not value articles. It does, however, determine the facts on which value rests, and buyers who understand those facts can judge for themselves whether a price makes sense. This guide describes the factors, not the numbers, because the numbers change and the factors do not.
Gemstones
Species. The starting point. Ruby, sapphire, emerald and diamond command the highest prices; spinel, tourmaline, garnet and quartz varieties sit below, in roughly that order, with many exceptions for fine material.
Natural versus synthetic. The largest single multiplier. A synthetic stone of identical appearance costs a small fraction of a natural one. This is why a report's natural or synthetic line matters more than any other.
Treatment. Untreated fine stones are rare and priced accordingly. Heated corundum, oiled emerald and stabilised turquoise are standard and priced as such. Glass-filled ruby, diffused sapphire and dyed material sit at the bottom. The extent of treatment (minor to significant) moves the price within each band. Natural, synthetic or simulant.
Colour. For coloured stones, most of the value. Hue, tone and saturation, with vivid, medium-toned, pure colours at the top. The Four Cs for coloured stones.
Clarity. Relative to the species. Eye-clean stones command more; inclusions that are visible or threaten durability reduce value.
Size. Price per carat rises with size for fine material, steeply in ruby and emerald where large clean stones are very rare, less steeply in species where large crystals are common. Two 1 ct stones do not equal one 2 ct stone.
Cut. Affects how the stone shows its colour and returns light; a poor cut discounts a fine stone; recutting costs weight.
Origin. A premium for prestige sources — when supported by a credible origin opinion. An unsupported origin claim is worth nothing. Can a laboratory tell where a gemstone came from?.
Market and context. Wholesale, retail, auction and insurance replacement values differ for the same stone. Prices move with fashion and supply.
Rudraksha
Mukhi count. Five is common and inexpensive; prices rise steeply away from five in both directions. One mukhi (round) and counts above fourteen are the rare extremes. Higher mukhi Rudraksha: rarity and fakes.
Origin. Himalayan (Nepali) beads command several times the price of Indonesian beads of the same mukhi, because of size and scarcity. Nepal vs Indonesian Rudraksha.
Size. Within an origin, larger beads cost more, sharply so at the upper end.
Naturalness of the faces. A bead with carved faces is worth its natural count, not its surface count.
Condition and form. Well-formed, round, symmetrical beads with clean grooves and no cracks or repairs command a premium over ordinary wearing-grade beads. Collector grade vs wearing grade.
Special forms. Gauri Shankar, Trijuti and other natural multiples are priced on rarity, and only when a laboratory has confirmed natural fusion.
Capping and setting. Silver or gold caps and settings add material cost; they do not add to the bead's value and can hide defects.
Crystals and organics
Material. Natural versus glass, dyed versus natural colour, reconstituted versus solid.
Treatment. Stabilised turquoise, dyed agate, heated amber — each discounts the untreated equivalent.
Natural versus cultured (pearls). A very large difference; natural pearls are rare.
Size, quality and matching for strands.
What a report tells you about price
Every factor above that concerns the article itself — species, natural or synthetic, treatment and extent, weight, dimensions, mukhi and compartment count, origin opinion, condition — is on a good report. What the report does not give is the number, because the number depends on the market and the context. Why a report does not include a valuation.
Using this when buying
Read the listing for each factor. A price that is low for the claimed combination — natural, unheated, fine colour, large, prestigious origin — is low because one of the claims is false. A price that is high for a common combination is a price to negotiate. Either way the report, obtained before the return window closes, converts claims into findings.
Frequently asked questions
Why are two rubies of the same weight so different in price?
Natural versus synthetic, treated versus untreated, and colour. Weight is the least of it.
Does a certificate increase the value of a stone?
It removes uncertainty, which makes the stone easier to sell and reduces the discount a buyer would apply for doubt. It does not change what the stone is.
Are Indonesian Rudraksha worth less because they are inferior?
They are smaller and more plentiful, not inferior. Price follows scarcity and size.
Is a stone a good investment?
The laboratory does not advise on investment. Fine, rare, documented stones have historically held value; commercial-grade material has not.
Why does the same bead cost different amounts from different sellers?
Margins, overheads and honesty vary. The bead's factors — confirmed by a report — are the constant.