January 2025 – Agate

In January 2025, agate was chosen as the mineral of the month. Agate is a microcrystalline variaty of the mineral quartz, which means that it consists of many tiny crystals. Agate usually forms colourful and striped aggregates. These often form in cavities in volcanic rocks such as basalt (so-called ‘vugs’).

Our agate comes from the estate of the biologist and ethnologist Therese von Bayern, who probably brought it back from one of her expeditions to Brazil.

Chemical formula: SiO2

Locality: Rio Grande do Sul, Brazil

Size: 2.5 x 9 x 7.4 cm

Weight: 312 g