| PROPERTY | International Std. ISO 13006/EN 176 Group Bla |
OPAL VALUE | Method of Testing |
| Deviation in length | ± 0.6% | ± 0.3% | ISO 10545 Pt 2 |
| Deviation in thickness | ± 5% | ± 5% | ISO 10545 PT 2 |
| Straightness of Sides | ± 0.5% | ± 0.5% | ISO 10545 PT 2 |
| Rectangularity | ± 0.6% | ± 0.5% | ISO 10545 PT 2 |
| Water absorption * | < 0.5% | < 0.5% | ISO 10545 PT 3 |
| Mohs Hardness * | > 6 | > 8 | EN 101 |
| Flexural Straightness * | > 35 N/mm2 | > 45 N/mm2 | ISO 10545 Pt 4 |
| Abrasion resistance | < 175 mm3 | < 144 mm3 | ISO 10545 Pt 6 |
| Breaking Strength * | 1113 N | 400 N | ISO 10545 Pt 4 |
| Density (g/cc) | > 2.0 | 2.4 | ISO 10545 PT 3 |
| Frost resistance | Frost proof | Frost proof | ISO 10545 PT 12 |
| Chemical Resistance | No Damage | No Damage | ISO 10545 PT 13 |
| Thermal Shock Resistance | No Damage | No Damage | ISO 10545 PT 9 |
| Colour Resistance | No Damage | No Damage | DIN 51094 |
| Thermal Expansion | < 9 x 10-6 | < 6 x 10-6 K-1 | ISO 10545 PT 8 |
| Stain Resistance | Resistant | Resistant | ISO 10545-14 |
| Moisture Expansion | Nil | Nil | ISO 10545-10 |
