Silver and gemstone necklace

[maryefine]

Hello, there are three marks on this necklace. A letter 'A'; a stamp with three geometric shapes (a silver mark?) and another mark - perhaps a maker's mark? I bought this rose quartz and amethyst necklace in the Czech Republic and would be fascinated to know its origin and date. The marks are tiny but we have managed to magnify them. Thank you. Mary