# Saltglass and the Shore

*A natural-history essay from "The Islands Observed", a Kelvarran miscellany.*

Walk any west-facing strand in the archipelago on the morning after a hard blow, and you will see
the islanders out before breakfast, heads down, walking the wrack line with the absorbed and
faintly guilty air of people looking for money. They are looking for saltglass, and to understand
Kelvarra you could do worse than start with what they are picking up.

Saltglass is the islanders' name for the dark natural glass of the archipelago: a volcanic glass,
black as a wet slate and glossier, that the old eruptions of Mount Sarn poured out in sheets and
seams long before there was anyone here to name things. Sarn has been quiet through the whole of
recorded history — a dormant volcano with hot springs on its flank for a memory — but its old
flows ring the island underwater and above it, and the Brann has been quarrying them ever since.
The sea does the work no lapidary would take on: it breaks the seams, rolls the shards for a few
centuries in the boulder strands, and delivers them up the beach as pebbles — smooth, black,
cold in the hand, and holding a green-edged gleam when you turn them to the light that no other
stone of the islands can offer.

The best of it comes ashore on Sarn itself, on the storm beaches below the old flows, where after
an equinoctial gale the wrack line can glitter with it. Ilvess gets its share on the western
strands at Corrie Ness, and Little Moriny a little, and the outer skerries — as the boatmen will
tell you with feeling — get the most and are the least worth the sail. A good piece is judged the
way pearls are judged, by depth and evenness; a pebble of true black with the green edge and no
grey bloom will change hands in the fish market for more than the fish do.

What the islanders have made of it says a good deal about them. Saltglass is Kelvarra's jewel, in
so far as the Republic can be said to go in for jewels: it is cut and polished for ring stones and
brooches, strung rough for luck, and set, by long custom, into the lintel of a new house — one
pebble for each soul under the roof, which is why an islander reading a strange doorway is
performing a census. A bride wears a piece of it; a boat carries a piece of it in the keel; and
the lamp room of every light in the archipelago has a pebble of saltglass on the sill, put there
by keepers for as long as there have been keepers, for reasons no two of them give alike.

The naturalist can add a little to the folklore without spoiling it. Fresh-broken saltglass is
sharp beyond any island metal, and the middens on Sarn show blades and scrapers of it going back
to the first settlement; the shard beds below the flows are, in effect, the Republic's oldest
tool works. The green edge that collectors prize is a thin-section effect — the glass is not
truly black but a deep bottle-dark, as a sliver held to the sun will show. And the grey bloom
that ruins a pebble for the jeweller is the slow work of the salt itself, the sea taking back,
molecule by molecule, what it spent centuries polishing. The Institute's geologists, who map the
old flows and keep an affectionate eye on the shard beds, are said to grade their fieldwork by
the pocketfuls they bring home; the present writer has seen the specimen drawers on Corran Hill
and can report that science and beachcombing are not, in Kelvarra, seriously distinguished.

Whether the supply is endless the islanders decline to wonder aloud. The sea has been generous
for as long as the wrack line has been walked, and the old flows are large, and Sarn — though the
hot springs whisper otherwise — keeps its own counsel about making more. The prudent visitor
buys a pebble in the fish market, hears the price, and concludes, correctly, that the sea is not
so generous as all that.
