Larvikite Tumbled Stone

Larvikite is a rock, not a single mineral - a feldspar-rich igneous stone from the Larvik district of southern Norway, where it cooled slowly deep in the crust. It is built almost entirely of feldspar crystals, and reads as a dark grey to near-black ground.

Its character is the schiller: a silvery blue-grey flash that slides across the cut surface as it turns. The flash comes from light scattering off fine layers within the feldspar crystals - the same optical family as the sheen of moonstone and labradorite, though larvikite is its own rock.

Honest naming: larvikite is sometimes sold as "black moonstone" or "Norwegian moonstone." It is neither - it is larvikite, a Norwegian feldspar rock, and the true name carries the better story. Mohs about 6 to 6.5.

Asked often

What is larvikite?
A feldspar-rich igneous rock from Larvik in Norway, dark grey to black with a silvery-blue flash. It is a rock built of feldspar crystals, not a single mineral, and it is named for the place it comes from.

Is it a kind of moonstone?
No. It is sometimes sold as "black moonstone" or "Norwegian moonstone," but it is larvikite - a different stone. The blue flash is the same optical family as a moonstone’s sheen, which is where the trade name came from.

What makes the blue flash?
Light scattering off fine layers inside the feldspar crystals, returning as a silvery blue-grey sheen that moves as the stone turns. It is structure and light, not colour or coating.

How do I look after them?
Wipe with a soft cloth. At Mohs 6 to 6.5 they wear reasonably well; spare them hard knocks, which can chip a feldspar along its cleavage.

1. Carried in a pocket or a bag, or held in the hand.
2. Kept in a small dish, on a desk, or on a shelf - each stone is a little different.
3. Wipe with a soft cloth; a feldspar rock, softer than quartz, so spare them hard knocks.

Each stone is tumble-polished and unique, so a set varies a little stone to stone. Many keep a stone where they will see it each day, or carry one in a pocket; that is a matter of preference.

Pocket stones to keep and carry. Wipe with a soft cloth; a little softer than quartz at Mohs 6–6.5, so spare them hard knocks, which can chip a feldspar along its cleavage.

• Stone: Larvikite · Norwegian feldspar rock
• Hardness: Mohs ~6–6.5
• Character: Dark grey to black · silvery-blue schiller
• Composition: Chiefly feldspar · a rock, not one mineral
• Form: Tumbled stones · polished, each unique · sold in a set
• Origin: Norway
• Care: Wipe with a soft cloth · spare hard knocks

Larvikite is one of the most widely used decorative stones on Earth. Quarried at Larvik in Norway and polished to bring out its blue flash, it clads bank fronts, lobbies, and monuments around the world; the stone trade knows the dark, flashing varieties as Blue Pearl and Emerald Pearl. It is the national rock of Norway.

For the moonlike flash that earned it its trade names, larvikite has been carried in recent traditions as a grounding, steadying stone - named here as what people believed. The flash is feldspar and light; what it steadies is the keeper’s.