Amethyst Craft adds a set of amethyst-themed blocks, items and mechanics.
Amethyst Mirror is the centerpiece. It is not a fake cubemap or a screen-space effect: a virtual camera renders the world again from the mirrored viewpoint into an offscreen buffer, which is then sampled back onto the mirror surface — a real planar reflection. Face two mirrors at each other and you get a mirror-in-mirror tunnel that darkens with every bounce and fades into the fog, so the tunnel no longer ends in a flat, dead patch.
Portal is a 1×2 two-block gate. Record a spatial anchor with the Phase Charm at two places and the gates pair up automatically. Walking through the opening teleports players and other entities with no delay, and each gate shows a live view of what lies behind its partner. Breaking one gate removes the other.
Also included: Time Termination and Day Night (speed up local ticks and the day/night cycle), Force Core (pushes mobs away), Space Button (54-slot portable storage), Years Talisman (auto-repairs your gear), Writing Desk (copies enchanted books), plus the Anger and Shield effects.
An Amethyst Cavern generates in your world, and the Mirror Boss waits inside — kill it with a pickaxe or simply hold your ground for 10 minutes to claim the loot chest.
Performance note: real reflections mean rendering the world multiple times per frame. Mirror count, tunnel depth and the stop threshold are all configurable, and reflection can be switched off entirely if it conflicts with shaders (Iris/OptiFine) — everything else keeps working.

