Genuine red corundum also known as ruby. Corundum is an aluminium oxide mineral and contains traces of iron, titanium and chromium which influence the crystals colour. With a hardness of 9 on the Moh's scale of hardness, corundum is used extensively in industry as an abrasive as it can scratch almost any other mineral except diamond. These particular samples are of red corundum and come from Madagascar and exhibit the crystals hexagonal class excellently. The samples are rough and have not been treated, yet exhibit a some what sub vitreous lustre. Available in a range of sizes, each crystal will supplied in a card tray with an information label, excellent for both serious collectors as well as educational bodies, where the samples can be used to display crystal systems.
Specimens are available in the following sizes:
- Small - Approximately 3 cm in diameter and approximately 50 grams in weight
- Medium - Approximately 4 cm in diameter and approximately 85 grams in weight
- Large - Approximately 5 cm in diameter and approximately 175 grams in weight