Mayco Jungle Gems CG786 Obsidian Crystal Glaze, 118 ml

Mayco Jungle Gems CG786 Obsidian – black crystal glaze for decorative ceramics

Mayco Jungle Gems CG786 Obsidian is a brush-on glaze for decorative ceramics. On bisque-fired ware it gives an opaque black surface with crystal effects. The glaze contains crystalline particles that melt and spread during firing, so every piece gets its own pattern. In the reference firing at 1015 °C, Obsidian is an opaque black base glaze with blue, green and brown crystals distributed in varying amounts.

The glaze is ready to use in the 118 ml container and suits vases, bowls and other decorative items. It is not intended for dinnerware and is not suitable for spraying.

Applying Obsidian

Shake the container well before each use, then stir so that the crystals are distributed through the glaze. Apply 2–3 even coats to bisque-fired ceramics with a fan brush and let each coat dry between applications. For the third coat you may need to stir the crystals up again so that the coverage stays even. Do not place any crystals near the base: they run during firing and can make the piece stick to the kiln shelf.

Firing and result

Mayco recommends firing at cone 06 to 05 (999–1046 °C). For comparison: cone 06 is approx. 998 °C and cone 05 approx. 1031 °C (in each case a guide value per Orton chart). At higher temperatures the colours become paler. At 1305 °C only the black base glaze remains and the crystals fade out completely. The glaze runs more than many others, and surface problems can occur. Make a test piece before glazing a larger item.

• Bisque firing: cone 04 (approx. 1063 °C, guide value per Orton chart)
• Glaze firing: cone 06/05, 999–1046 °C
• Reference firing: 1015 °C with blue, green and brown crystals

Mayco Jungle Gems CG786 Obsidian product details

• Manufacturer: Mayco, Jungle Gems Crystal Glaze series
• Manufacturer's art. no.: CG-786
• Colour: Obsidian, black base glaze with blue, green and brown crystals
• Coverage: opaque
• Contents: 118 ml (4 fl oz)
• Firing recommendation: cone 06 to 05, 999–1046 °C
• Application: brush, 2–3 coats, not suitable for spraying
• Use: decorative only, not for dinnerware

You will also need: fan brush; bisque-fired ceramics (bisque firing up to cone 04, approx. 1063 °C, guide value per Orton chart); kiln

Not suitable for dinnerware or food contact (Not Dinnerware Safe). The surface may crackle, so use for decorative purposes only. According to ACMI, the AP seal (Approved Product) means: exempt from hazard labelling. Full safety data sheets (SDS) are available at MaycoColors.com.