Gemstone Library · 2 min read
Ruby: Red Corundum, Colour and Clear Descriptions
Understand ruby identity, the importance of colour and the questions to ask about a particular red gemstone.
| Detail | Reference |
|---|---|
| Material | Red corundum |
| Mohs hardness | 9 |
| Birthstone association | July |
| Still ask | Natural/laboratory-grown status and treatments |
What makes a ruby a ruby?
Ruby is the red variety of corundum. Chromium is responsible for its characteristic red colour. GIA lists ruby at 9 on the Mohs scale, a reference to scratch resistance rather than a promise that it cannot chip.
Red appearance alone does not establish ruby identity. A red spinel, a manufactured imitation and a laboratory-grown ruby need different descriptions even if they look similar in a photograph.
Compare the red you actually see
GIA emphasizes colour as a major ruby quality factor. Our practical suggestion is to compare stones in the same lighting and ask for a slow, neutral-light video. Check whether the centre looks consistently bright or becomes very dark as the piece moves.
Keep size, dimensions and setting in view. An attractive close-up can make a small ruby look much larger than it will appear on your hand.
Put identity and treatment in writing
Ask whether the ruby is natural or laboratory-grown and what treatments are disclosed for the specific stone. Do not interpret an omitted treatment description as a claim of no treatment. A seller's colour adjective is not a laboratory finding about origin.
For a significant purchase, discuss an appropriate independent report and match its identifying details to the stone offered. Keep the invoice and report together.
Choose for the complete piece
Consider how the setting protects the stone and how the jewellery will be worn. Ask for care instructions that account for the stone, any treatment and the surrounding metal.
For a July gift, ruby's traditional birthstone association can supply a personal theme. It does not determine authenticity, value or suitability for every wearer. Choose a clear description and a design the recipient will enjoy.
Sources & further reading
Morolia editorial guide. Material facts are supported by the linked references; buying and styling suggestions are editorial guidance. Gemstone coverage is educational and does not indicate current inventory. Follow care instructions for your particular item. Sources do not imply endorsement of Morolia.