Silica in plant tissues has been suggested as a component for enhancing mechanical properties, and as a physical barrier. Pineapples present in their shell and bracts rosette-like microparticles that could be associated to biogenic silica. In this study, we show for the first time that silica-based microparticles are co-purified during the extraction process of nanocellulose from pineapple (Ananas comosus). This shows that vegetable biomass could be an underappreciated source, not only for nanocellulose, but also for a highly valuable sub-product, like 10 µm biogenic rosette-like silica-based microparticles. The recovery yield obtained was 7.2 wt.%; based on the dried initial solid. Due to their size and morphology, the microparticles have potential applications as reinforcement in adhesives, polymer composites, in the biomedical field, and even as a source of silica for fertilizers.