The famous family Gerritsen, silversmiths and factory founders history
In 1866, Johannes Albertus Adolf Gerritsen(1840-1925) founded his jewelery company in Amsterdam, which in 1903 was converted into the N.V. Nederlandsche Fabriek voor Gouden en Zilveren Werken voorheen J.J.A.Gerritsen/ N.V.Dutch Factory for Gold and Silver Works formerly J.J.A.Gerritsen.

Maker's mark
G.Z. for; Johannes Albertus Adolf Gerritsen, this particular mark registered in the cities of Amsterdam and Zeist 1906/?1908.
His sons Johannes Albertus (Albert) (1874-1946) and Marius Johannes (1882-1954) also worked in the factory. Since c. 1895 the company was established at the Looiersgracht in Amsterdam; in 1904 it moved to Zeist (Karpervijver). The two brothers Albert and Marius Gerritsen formed the management. Mark used GZ in rectangle for Ned. Fabriek van Gouden en Zilveren Werken (previous know as J.A.A. Gerritsen), used ? 1908-? 1924.
In 1909 Marius left his his father's factory. In 1925 the management of the N.V. Dutch Factory for Gold and Silver Works was expanded and the name was changed to; N.V. (from 1926 Koninklijke/ Royal) Nederlandse Fabriek voor Gouden en Zilveren Werken Gerritsen en Van Kempen/
Dutch Factory for Gold and Silver Works Gerritsen and Van Kempen. In 1960 this factory merged with the company Begeer from Voorschoten and became the name N.V. Koninklijke Nederlandse Fabrieken van Gouden en Zilveren Werken Van Kempen en Begeer/
N.V. Royal Dutch Factories of Gold and Silver Works Van Kempen and Begeer
N.V. Nederlandsche Fabriek voor Gouden en Zilveren Werken voorheen J.J.A.Gerritsen/ N.V.Dutch Factory for Gold and Silver Works formerly J.J.A.Gerritsen.

Maker's mark/factory mark
Gz.(conjoined); N.V. Nederlandsche Fabriek voor Gouden en Zilveren Werken voorheen J.J.A.Gerritsen, this particular maker's mark used ?1908-?1924
N.B. In 1910, Marius Johannes Gerritsen founded the Eerste Nederlandse Fabriek van Nieuw-Zilverwerken/
First Dutch Factory of New-Silver Works, the later
Gero. In 1922, Marius Johannes Gerritsen, being honorably dismissed as technical director after refusing to sign an annual report that he said gave an incorrect picture of the factory left, and started a new company, de N.V. De Nederlandse Metaalwarenfabriek/ the N.V. The Dutch Metalwork Factory, later called
Sola.
The Gero factory in the city of Zeist, founded 21 0ktober 1912
Gero short for Gerritsen & Co
Founded under the name;
Eerste Nederlandsche Fabriek van Nieuw Zilverwerken, formerly known in 1910 under the company name;
MJ Gerritsen & Co., has become a household name in the Netherlands, which stands for virtue and quality.
The Gero factory was founded by Marius Johannes Gerritsen (1882-1954) which in 1909 left his his father's factory to start his own business, along with his brother in law and business partner Julius ter Beek (1888-1967). Marius Gerritsen together with his brother in law Henri Simonis became the first directors. As the result of a conflict about the balance in 1921, between Marius Gerritsen and H.Simonis his brother in law and as such also between Marius Gerritsen’s father, Marius was granted a honorable discharge in 1922. After he left Gero Marius Gerritsen founded Gerrowé, later renamed
Sola.
Although Gero was hit by the impact of the First World War it managed to introduce various new collections made in Gerozilver and Gero-alpacca. Throughout its existence the Gero factory used a large number of different alloys. The Gero factory made its products in 'New-silver', also called Alpacca and in a silver plated white metal called Gerozilver. However the spoons and forks made out of Alpacca, a white coloured alloy of roughly 60%copper, 20% nickel, 20% zinc & 5% tin, discoloured rapidly and a layer of chromium was applied over the Alpacca and called Gromalca . In addition Gero made products in pewter, called Gero-tin. The name
Gerozilver caused confusion and in 1952 New Hallmark rules forced Gero to change the name into
Gero Zilvium
Worldwide recognition
In the early years the company flourished had no competition, the first company to produce quality cutlery for a cheap price. In 1922, a Gero factory was opened in Copenhagen, Denmark to produce for the Scandinavian market. Sales offices were opened in England, Belgium and Germany and the Dutch East Indies and South America were important markets. The Gero factory grew in those years into a well-functioning company. The 12.5 year anniversary of the factory was celebrated in 1925 with the slogan "Gero spans de Kroon" and in the same year the factory name of;
Eerste Nederlandsche Fabriek van Nieuw Zilverwerken, voorheen M.J. Gerritsen & Co. Was changed in;
Gerofabriek, Fabriek van Nieuw Zilverwerken (Gerofactory, Factory of New Silverworks)
In 1929 the Gero factory, like many other companies, had to deal with the consequences of the Stock Market Crash in America. As a result in 1931, the factory in Copenhagen was closed. In order to meet the demand for cheaper cutlery Gero Zilmeta was introduced, a stainless steel product which required no maintenance and in addition, it was highly suitable for the manufacture of pans, bowls and serving utensils. The Alpacca and Gromalca disappeared from the range of products and replaced by stainless steel Gero Zilmeta.
Besides cutlery soon also other utensils were made as dinnerware, napkin rings, finger bowls, bread baskets and candlesticks.
In the early years the Gero factory had no own designers. In 1923 the Gero factory teamed up with the famous Dutch decorative artist
Chris van der Hoef (CJH).

From 1927 products designed by
Georg Nilsson (GN) in Copenhagen were also made by Gero in Zeist. And after the closure of the Gero factory in Copenhagen in 1933, Georg Nilsson works in the Gero factory in Zeist Holland until his retirement in 1957. In the 1950ties Georg Nilsson designed child's cutlery Fairy tale sets. See for an example;
http://www.925-1000.com/forum/viewtopic ... 45#p147745

Georg Nilsson has been responsible for most of the designs made by Gero, the characteristic; animal motifs, flower and leave motives, hammered surface but also sleek & functional designs.
Jan Eisenloeffel JE in circle

In 1929 Gero introduced the cutlery set model nr. 70, designed by Jan Eisenloeffel, a great commercial success, and still made in 1954. Gero claimed the Cutlery set model nr.70, one of the best Dutch Arts & Crafts Industrial design.
Cooperation with other factories.
Copier Gero liqueur decanter - Andries Dirk Copier, 1930 (Nationaal Glasmuseum)
Leerdam elixir bottle and glass with Gero- tin, design Georg Nilsson. Bottle height 15 cm and glass 11 cm
Plazuid (Plateelbakkerij Zuid-Holland) pottery vase, with Gero (Zeist) pewter mount, art deco period, hight 11 cm, made ca.1930.
Leerdam Glass Factory/designer Andries Copier, cooperation between 1930 and 1933; candlesticks, flower vases, condiment sets and liqueur sets. In the early thirties, there is cooperation with the
Plateelbakkerij Zuid Holland Gouda. Earthenware Gouda vases, bowls, candlesticks, ashtrays, bottles and such were in Zeist decorated with Gero-tin. The cooperation with design artists and other factories rose to fame of the Gero factory and participating in important national and international exhibitions. After World War II the Gero factory opened a new branch in Nieuw- Weerdinge, near Emmen, to increase production capacity.
To further increase the production capacity companies/factories were taken over by Gero: Hollandia Plate Hilversum, NV Reppel in Belgium and the German firm P. Bruckmann & Söhne in Heilbronn. The products produced by Bruckmann were manufactured from 1965 under the name 'Gero sterling silver', however, this company proved not to be profitable. In addition, the Gero factory could not handle the fierce international competition and lost market. In 1974 the Gero factory in Zeist was closed. The Gero factory in in Nieuw-Weerdinge managed to stay open in a much reduced form. In 1985 Gero factory/brand name is taken over by the Royal Van Kempen & Begeer in Zoetermeer. Today Gero is still produced .
(BK Cookware: The brand Gero and the brand BK are part of BK Cookware bv. BK Cookware bv. is part of the Royal Delft Group. De N.V. Koninklijke Delftsch Aardewerkfabriek "De Porceleyne Fles Anno 1653" (Royal Delft) is the leading producer of authentic Delft Blue ornamental earthenware and modern earthenware. In January 2008, Royal Delft acquired crystal producer Royal Leerdam Crystal and since September 2008 BV Koninklijke Van Kempen & Begeer (owner of the brand names: BK, Gero, Keltum and Royal VKB).
Gero factory maker’s mark for silver item made up till 2000:
Gero silver plate trademark:

The D in a circle is not a date letter but a design letter.The N in a circle is a production letter or production mark and various letters of the alphabet were used to keep control of manufacture. These production letters are on all silver-plated items as from 1917.
The Gero factory in Denmark used a capital P, probably for Plated.
In 1962, the production letters were placed in a square instead of a round circle.
Production letters used on plated items as such have no reference to a particular year and to my knowledge a Gero silver plate date/year/mark letter chart does not exist.
Gero silver plate the numbers 20, 40, 90 or 100 indicates the grams of pure silver used to silver plate 12 spoons and 12 forks. The higher the number, the higher the thickness of the silver layer (skin) or quality; 20, 40 90 or 100 grams of silver has been used. After 1965 Gero used only 100 grams.
Gero Sterling:
Gero with Dutch (hall)marks:
From left to right: Gero maker's mark for silver, 2nd standard mark silver, Minervahead/assay office mark and date letter P for: 1925
Gero Copenhagen silver plate trademark two towers:
In 1922 Gero opened a factory in Copenhagen, Denmark which produced mainly products for the Danish & Nordic markets. Georg Nilsson born in 1888 Denmark and trained by the famous"Georg Jensen" was hired by Gero in Copenhagen as a designer & craftsman. After the closure of the Gero factory Copenhagen, Georg Nilsson settled in the Netherlands. Georg Nilsson continues to work for Gero in Zeist until he retired in 1957. His work is characterized by, at that time 'peculiar', hammered surface and the use of animal ornaments. Before World War II Nilsson designed cutlery models that were characterized by forms of art deco, hammered form or in the form of a cartouche. After the war, his designs became sleek and functional.
Gero factory used the services of famous designers who marked their designs: Georg Nilsson (GN), Theodorus Hooft (TH) pewter only, Chris van der Hoef (CJH), Jan Eisenloeffel (JE in circle), Rinze Hamstra (RH) pewter only and Andries Copier (C in circle )

Designer
Dick Simonis (DS in circle), son of the director Henri Simonis, started in 1944 to work for the Gero factory until 1974. After World War II it was in the first place important to bring production back on track and there was no attention to launch new models. In 1955 the Gero factory stopped the production of pewter objects, and only Zilmeta and Zilvium objects were produced. From 1959 Gero also produced Zilduro products with a higher nickel percentage compared to Zilmeta objects.
In 1957, after Georg Nilsson retired, the Gero factory employed
Ib Jensen, a well-known designer from Denmark, and the son of Georg Jensen. In 1962 Ib Jensen returned, after completing a few designs back to Denmark. Dick Simonis was the only permanent designer employed at the Gero factory. The technically well-designed objects of Simonis are characterized by a sober unadorned line. The influence from Denmark where he had received part of his training is herein clearly visible. A Gero Zilmeta cookware designed by Simonis in 1958 received awards in Brussels and Canada 'because of high quality coupled with a pleasing shape'.

Cookware set, Gero Zilmeta, design Dick Simonis, 1958

Gero Hollandia plate for Hotels & Restaurants.
The factory: Hollandia Plate made exclusively cutlery and items for restaurants, shipping, etc. For large users.
In 1963 the Gerofabriek took over the Hollandia Plate factory in Hilversum and the brand: Gero-Hollandia Plate came into use.
See:
http://www.925-1000.com/forum/viewtopic ... 81#p159381
100 jaar Gero;
http://www.gero.nl/webdocs/GERO_100jaar.pdf
Gero silver plate trademark name: Zilvium
Gero stainless steel trademark names; Zilmeta, & Zilduro (high nickel%)
Peter.