The mineralogist behind the stones.
Sergey Marianovich buys from the people who own the deposits, sits across the table from the cutter, and brings home only the stones worth keeping.
Found by hand, before he knew what they were worth
Sergey found his first stones himself, as a child, in the tailings of the Malkhan deposit north of Lake Baikal – tourmalines, pulled out of spoil with his own hands. At a mineralogical exhibition someone offered to trade them for a Russian emerald crystal from the Malysheva Mine in the Urals. He agreed, not because he understood the value of the deal, but because he was certain the stone had to be his. Twenty years on he describes it as the principle he still works by: a fair exchange between two people who understand what they are looking at.
An architecture no one designed
As a teenager he read Alexander Fersman’s Entertaining Mineralogy, which described the crystal lattice as the height of natural order – every atom in its precise place, a flawless geometry rising out of the chaos of the amorphous world. Inside a diamond, an emerald, any crystal, there is an architecture nobody drew. That is the conviction the business rests on: a stone is a frozen moment of absolute order, formed millions of years before anyone decided what it was worth.
“I would rather place one stone that is truly right than a hundred that are merely available.”
Finding what others walked past
On expeditions with the MSU Geological School, which he joined while still at school, the groups often numbered around forty. At Slyudyanka, south of Baikal, the whole party searched all day for lavrovite – a mineral found nowhere else on earth, and rare enough that a genuine find is an event even there. He was the one who found it: a richly colored druse on matrix. At the same site he was also the only one to turn up a crystal of blue spinel. It happened again at deposit after deposit, and he has never had a rational explanation for it. He simply knew where to look.
Moscow to New York
Born and raised in Moscow, he went through a specialised chemistry school while studying at the MSU Geological School in parallel, and spent his field seasons on expeditions across Russia. Still in high school, he taught chemistry and lectured publicly on minerals and gemstones at the Polytechnic Museum. He began trading at Moscow’s mineralogical exhibitions at fourteen, went on to win two All-Russian geology olympiads in the mineralogy section, and wrote and defended two scientific papers. He moved to New York in 2019, completed his GIA coursework and a degree in business, has exhibited at the Tucson Gem Show every year since 2020, and founded Marianovich Gems with his family in 2024.
Straight from the deposit
The same instinct that found a lavrovite druse nobody else could see shaped how this business is built: through direct, long-standing relationships with the people who own the deposits themselves – not markets, not middlemen. Close ties with the owners of horsetail demantoid, color-change alexandrite, Russian emerald and tourmaline workings mean these stones reach you very nearly first-hand.
In 2026 that approach let us offer something the Western market had never seen: unheated sapphires from the Sutara deposit in the Russian Far East. The deposit is now closed – nothing more will ever be mined there. We were able to acquire everything that had already come out of the ground, and we are still cutting through that reserve today. A handful of specimens remain in private hands inside Russia, but no one else holds anything close to our volume. In every practical sense, we are the last hands these stones will pass through.
The family’s own collection holds the Pamir Rose: a 285-carat carved spinel from Kuh-i-Lal, the mine in the Pamir Mountains that gave the world its great “balas rubies,” and by weight the fourth-largest spinel ever documented from it. Discover the Pamir Rose
Bought with confidence
Every significant stone is offered with transparent disclosure of origin and treatment and, where it matters, a report from a leading laboratory – GIA, GRS, or IGI. Because we buy directly from cutters and sources, what reaches you is honest in both price and provenance. Whether you are a collector, a jeweler, or building a lasting store of value, the guidance is the same: unhurried, candid, and entirely yours.
I have never chased fame, money or scientific recognition. What matters is reputation, and the kind of relationships that last – with people who see, in a stone, a little more than a chemical formula or a price tag.
Sergey Marianovich – President
Rare by nature, chosen by hand.