At first sight maker's mark
"А·Н" looks like a mark of August Frederik Hollming (Август Фредерик Холминг; 3 December 1854 – after 1915) who was a Finnish silver- and goldsmith, and a Fabergé workmaster. He was born in Loppi, Finland, the son of a bookkeeper, Anders Gustaf Hollming of Lovisa, and of Katarina Petterson of Nykarleby. Hollming was apprenticed to the goldsmith Carl Friedrich Ekholm in Helsinki at the beginning of the 1870s. In 1876, he settled in St.Petersburg and registered as a goldworker.
In 1880, he qualified as a master and opened his workshop at 35 Kazanskaya Street; he was soon thereafter hired by Fabergé. He had three sons with Erika Gustava Abrahamsson (1856—1909). In 1900, the Hollming workshop moved to 24 Bolshaya Morskaya, under the same roof as Fabergé. He mainly made cigarette cases in silver, gold, and enamel; miniature Easter Egg; and small gem-set, enameled jewels such as cuff-links, brooches, and pins /many of which he manufactured for the House of Fabergé/.
The eldest son August Väinö Hollming (1885—1934) inherited the workshop after his father's death in 1913. He ran the workshop with Otto Hanhinen, his father's assistant until 1915.
Postnikova-Loseva defined August Frederik Hollming mark as:
"Холминг Август Фредерик (Hollming August Fredrik) (родился в 1854 году в Финляндии, умер в 1915 году), приехал в Петербург, где стал золотых дел мастером и ювелиром, в 1898 г. имел мастерскую и работал для фирмы Фаберже. На клейме мастера изображены инициалы на английском языке "A" и "H", между букв стоит точка. Форма: Прямоугольник.
Holming August Fredrik (born in 1854 in Finland, died in 1915), came to St. Petersburg, where he became a goldsmith and jeweler, in 1898 he had a workshop and worked for the Faberge company. The master's mark shows the initials in English "A" and "H", with a dot between the letters. Form: Rectangle."
Source: Marina Mikhailovna Postnikova-Loseva
Index of Russian marks on products made of precious metals of the 17th-20th centuries/Марина Михайловна Постникова-Лосева Указатель русских клейм на изделия из драгоценных металлов XVII-XX вв.
Breast star maker's mark have an oval form. Also in Hollming's personal mark between "A" and "H" stands not a dot but a six ray star /that sometimes looks like a dot/.