Description: These rubber bases—technically known as rubber bungs—are stoppers originally designed to fit into the mouths of glass vials. We repurpose them to hold water inside our glass bell jars, which are most commonly used for displaying opals.

In fact, 99% of the time, this glass bell jar and rubber base combo is used specifically for opals that need to stay in water. This includes any opal sold in water, whether from us or another vendor. Some opals can be cured and transitioned out of water; others cannot. For a detailed guide on which opals can be cured—and how to do so—please see our blog post on the opal curing process.

When displaying opals in water, we recommend using a mix of distilled water and a few drops of bleach (about 3–5 drops per ounce) to prevent algae growth. The bleach will not damage any variety of opal.

The rubber bases are intentionally dense and heavy to prevent the bell jars from tipping over. Some rubber bungs may have excess material that protrudes slightly beyond the edge of the bell jar. While still functional, this can be visually distracting. If you'd prefer a cleaner look, you can use a brand new box cutter to slice the rubber base in half; you can cut as much off as meets your aesthetic needs/purposes. With one firm, controlled motion, it will cut cleanly and improve the jar’s aesthetic. Click here for the bell jar listing that goes with these rubber bases.

Made In: China

Small
Dimensions: 2cm (height) x 1.8cm (wide end) x 1.4cm (narrow end)
Weight: 5.15g
Base fits with Bell Jars of this size: 18mm x 18mm x 50mm and/or 20mm x 20mm x 30mm

Medium
Dimensions: 2.5cm (height) x 2.4cm (wide end) x 1.6cm (narrow end)
Weight: 10g
Base fits with Bell Jars of this size: 25mm x 25mm x 40mm

Large
Dimensions: 2.5cm (height) x 4cm (wide end) x 3.3cm (narrow end)
Weight: 36g
Base fits with Bell Jars of this size: 40mm x 40mm x 50mm and/or 40mm x 40mm x 90mm

Material: Rubber 

Quantity: 1pc