Postalco Mineral Key Holder Ruby Zoisite

The Postalco Mineral key holder replaces the traditional key ring with a straight brass rod featuring a screw cap – and at one end, a stone of Ruby Zoisite, hand-cut and polished by traditional Japanese stone craftspeople. Ruby Zoisite displays a characteristic pattern of deep ruby red and matte green, which varies slightly in each piece. The brass is solid-cast; the stone is neither dyed nor chemically treated.

Features

• Keys in a row, not in a bunch: All keys sit side by side on a straight brass rod. Frequently used keys positioned at the edge can be grasped blindly – without searching through a bunch.
• Screw cap in solid brass: The stone serves simultaneously as the closure cap. Unscrew, thread keys on or off, screw back on – no spreading, no bending.
• Natural stone, untreated: Ruby Zoisite is neither dyed nor sealed. The colour, grain, and texture of each stone are the result of its geological history – no two pieces are identical.
• Brass patinas with use: Where your thumb runs across the metal daily, it begins to gleam. The stone itself becomes more matte and tactile over time – both are not faults but wear marks that characterise the object.
• Hand-crafted in Japan: Postalco works with family-run stone workshops in Japan. Each stone is individually hand-cut and ground.

Use & Tips

• Organise your keys: House, car or office keys can be arranged in a fixed sequence on the rod. Once you know the order, you can find the right key without looking.
• Number of keys: The rod holds a manageable number of flat keys – for a compact everyday setup, not for a large caretaker's bunch.
• Brass care: Hand-tighten the screw cap regularly; do not use tools to tighten as this can damage the thread.
• Stone care: Wipe with a damp cloth and dry immediately. Avoid hard impacts – natural stone can chip or crack. Ruby Zoisite is, unlike sodalite and lapis lazuli, less sensitive to water and salt.
• Allow patina to develop: The brass does not need polishing. The developing colour tone is part of the concept – Postalco designs objects for daily use, not for display cabinets.

For Mineral Enthusiasts

Ruby Zoisite – also known as anyolite – is an aggregate of zoisite (green to greyish-green) and ruby inclusions (opaque deep red), occasionally supplemented by black hornblende particles. The juxtaposition of minerals forms under high pressure and high temperature in metamorphic rock; the colour distribution is never uniform and never reproducible. Because the stone is hand-cut, the cutting technique determines which colour proportions predominate – each piece shows a different balance between red and green. The surface feels cool and slightly textured; the weight sits noticeably heavier in the hand than a pure brass rod.

Technical Specifications