The question always comes before the order
A jewellery buyer asks something. Is it solid gold, what size is that, will it tarnish, can you resize it. That conversation is the sale, and it happens in messages whether or not you have a website.
Putting the catalogue in the same chat means the browsing and the asking are one motion instead of two.
Materials and sizes belong on the piece
Most of those questions have one permanent answer. The metal, the stone, the ring sizes you make. Those live on the product as attributes and in the description, so the shopper reads them at the moment they wonder.
Sizes work as options, each with its own stock, which means a size you have run out of cannot be ordered and refunded a week later.
A short catalogue is an advantage
Jewellery shops do not need a thousand items. Ten pieces photographed well outsell fifty photographed badly, and a small catalogue is exactly what a phone screen shows best. Categories by type keep it walkable: rings, pendants, earrings.
Photography carries everything
The layout gives each piece a large card because that is the whole product. Several ready-made designs suit jewellery, with darker palettes and quiet type that let metal and stone do the work. You apply one and adjust the accent to your brand.
What to do about custom orders
Bespoke work does not fit a cart, and it does not need to. List the made-to-order pieces at their starting price with the detail in the description, and take the specifics in the chat the order arrives in. The Mini App handles the browsing; you handle the part that needs a person.