Matsubokkuri - Storm Glass+ Amethyst | Glass Pen

Tip this pen and you'll hear it before you see it shift: a soft, sandy rustle as the amethyst points inside slide against the glass and against each other. Unlike the tumbled stone fragments in other Storm Glass+ pens, what's sealed in this shaft is a small cluster of raw amethyst — natural crystal points still attached at their base, the way they'd have grown in a geode, rather than cut or smoothed into uniform chips.

Why This One Looks Different

Amethyst is quartz coloured by trace iron, and that colour rarely fills a crystal evenly — most pieces run from deep violet at the tip to pale lilac or clear toward the base, which is exactly the gradient visible in this pen's cluster. Because the points are left in their natural form rather than tumbled smooth, light catches each facet separately as the pen tilts, instead of scattering off rounded stone the way it does in the ruby or obsidian versions.

The Pen Itself

Every Storm Glass+ pen is shaped freehand over an oxygen torch by Kiyoshi Matsumura at Glass Studio Matsubokkuri in Suginami, Tokyo. The shaft is hollow rather than solid, keeping the pen light in hand, with a collar at the base of the nib to stop it rolling off the desk mid-sentence.

Specifications

• Total length: approx. 175mm
• Shaft diameter: approx. 12mm
• Weight: approx. 21g
• Contents (non-toxic): water, ethanol, natural camphor, ammonium chloride, potassium nitrate, raw amethyst cluster
• Nib width: Fine (F), Medium (M), or Broad (B)
• Handmade in Japan

Using and Caring for a Storm Glass Pen

Dip the nib fully before writing — the spiral-cut grooves hold enough ink for several lines per dip. Because the amethyst points are left unpolished, they catch very slightly against the glass as they shift rather than sliding freely, which is what produces the pen's quiet rustle; it's a normal part of how this particular stone was sealed in, not a flaw. Rinse under lukewarm water after use and avoid sudden temperature swings, which can stress the glass shaft.

Frequently Asked Questions

Why does this pen make a sound when I tilt it?
The amethyst inside is a cluster of natural, unpolished crystal points rather than tumbled stone, so the facets catch gently against the glass and each other as they move — a texture unique to this Storm Glass+ colour.

Is the colour gradient from purple to clear intentional?
Yes, in the sense that it's left untouched: amethyst naturally deepens in colour from base to tip, and Matsubokkuri doesn't alter or evenly dye the stone, so each cluster shows its own natural shading.

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