David-Andersen and Norwegian Enamel: Reading the Marks
The butterflies, leaves and harlequin discs in glassy colour over Norwegian silver are one of the most collected twentieth century genres. Three workshops made most of it, all three signed their work, and the enamel itself tells you how carefully it has been treated.
Norway built an export industry out of enamel on silver, and it is still the country's most recognisable contribution to the jewelry box: butterflies with translucent wings, sterling leaves in soft green and blue, harlequin discs of many colours, and the plique-a-jour work that holds colour in an open frame with no backing at all. The pieces are signed, marked and dated more helpfully than most, so identification here is a matter of reading rather than guessing.
The three names to know
David-Andersen, founded in Oslo in 1876, is the name most often on the back. Its marks run through several forms, with the modern D-A in a shield being the one collectors meet most, alongside NORWAY and the standard, usually 925S for sterling and 830S on earlier or lighter work. The company produced both the mass-market butterflies and leaves and, from the 1950s, serious modernist work by designers including Willy Winnaess and Uni David-Andersen.
Marius Hammer of Bergen, working from the late nineteenth century, is the maker behind a great deal of early plique-a-jour and the small enamelled spoons that travelled home in every tourist's luggage. His mark is often simply an M with a hammer or the name in full, with 830S.
J. Tostrup, in Oslo since 1832, is the third of the trio, historically the most ambitious in plique-a-jour and a serious silversmith in its own right.
Beyond them, Aksel Holmsen, Ivar Holth, Einar Modahl and Arne Nordlie appear constantly, and all signed. An unmarked Norwegian enamel piece is unusual enough to be worth a second look.
Standards, dating and the guilloche question
Norwegian marks give you the maker and the standard, and the standard alone brackets the age: 830S is the older continental norm, 925S the sterling that dominates after the middle of the century. NORWAY as a country mark suggests export production, which is to say most of what circulates. Style dates the rest: naturalistic butterflies and leaves are the long-running commercial line, the geometric and asymmetric modernist pieces belong to the 1950s and after, and true plique-a-jour work, where light passes through the enamel like a window, is both older and considerably more valuable.
Most of the coloured surfaces here are guilloche enamel, transparent colour laid over an engine-turned silver ground so the pattern moves under the glass. The guilloche article covers how that ground is made and why it cannot be faked by printing.
Condition, which is nearly everything
Enamel is glass, and glass chips. Value in this genre is governed by the state of the surface more than by the maker's name.
| What to check | Why it matters |
|---|---|
| Chips at edges and high points | The commonest fault. Even small losses cut value sharply, since invisible repair is effectively impossible |
| Hairline cracks under raking light | Often missed in photographs, and they spread |
| Cloudiness or crazing | Usually heat or chemical damage, frequently from cleaning |
| Repolished silver around the enamel | Suggests a repair or an over-enthusiastic clean |
| Pin, hinge and catch | Period fittings, working smoothly, no solder blobs |
Cleaning follows from the material. Never use an ultrasonic cleaner, never soak, never apply silver dip, which attacks the enamel edge, and never polish across the boundary between metal and glass. A soft dry cloth on the silver and nothing at all on the enamel is the whole regimen.
What the market pays for
Ordinary butterflies and leaf brooches remain among the friendliest entries in twentieth century collecting, priced for their charm rather than their metal. Prices climb for plique-a-jour, for large or complex pieces, for full sets, for the named modernist designers, and for anything in genuinely unchipped condition. Since the enamel decides the price and the enamel is what a photograph flatters, this is a genre where you ask for a raking-light picture before you buy, and where sellers who supply one without being asked are telling you something about themselves.
Frequently asked questions
What does 925S mean on Norwegian silver?
Sterling silver, 925 parts per thousand, with S for silver in the Scandinavian convention. The older 830S indicates a lower standard and generally an earlier piece.
Who made Norwegian enamel butterfly brooches?
Most commonly David-Andersen of Oslo, with Aksel Holmsen, Ivar Holth, Arne Nordlie and others producing similar work. Nearly all of it is signed on the reverse.
What is plique-a-jour enamel?
Enamel held in an open framework with no metal backing, so light passes through it like a stained glass window. Marius Hammer and J. Tostrup are the celebrated Norwegian makers of it, and it is the most valuable form.
Can chipped enamel be repaired?
Not invisibly. Refiring risks the whole piece and cold fills are detectable. Assume a chip is permanent and price accordingly.
How should I clean enamel jewelry?
Dry cloth on the silver only. No ultrasonic cleaner, no soaking, no silver dip, and nothing that crosses the join between metal and enamel.
Is Norwegian enamel jewelry valuable?
Common brooches are affordable; plique-a-jour, large or complex designs, named modernist designers and mint condition pieces command considerably more. Condition of the enamel outweighs almost everything else.