Stone 02 · Gemstone guide
Ruby
Manikya
Ruby is the red variety of corundum. Chromium contributes its red colour, and natural stones often contain growth features that help gemologists interpret origin and treatment history.
Gemological register
- Mineral
- Corundum
- Composition
- Aluminium oxide
- Crystal system
- Trigonal
- Mohs hardness
- 9
- Refractive index
- About 1.762 to 1.770
- Specific gravity
- About 4.00
Colour
Colour is a range, not a shorthand.
Ruby covers red hues from purplish red to orangy red. Tone, saturation, colour distribution, fluorescence and the lighting environment all influence its face-up character.
Clarity and character
Read inclusions in context.
Needles, healed fissures, crystals and colour zoning may be visible. Some inclusions support identification, while surface-reaching fractures require particular attention during setting and care.
Treatment disclosure
Ask what changed and how it was detected.
Heat treatment is common. Diffusion, fracture filling with glass or other substances, and residue from heating require distinct disclosure because they affect identity, appearance, durability or care.
Setting practice
The mount answers the material.
The setter maps fissures and corners before applying pressure. Prongs or a bezel should secure the stone without obscuring its colour or placing force over a vulnerable feature.
Care
Care follows the individual record.
Mild soapy water is generally suitable for untreated and heat-only ruby. Filled or composite material needs more cautious handling, and powered cleaning should never be assumed safe without the treatment record.
Sourcing questions
Questions worth carrying to the desk.
- 01Is the material natural, synthetic or composite?
- 02Is there evidence of heat, diffusion, filling or residue?
- 03Is a geographic origin opinion supported by an independent report?
- 04Are surface-reaching features relevant to setting or care?
Kundali note
Ruby is traditionally associated with Surya in Jyotish. A chart reading considers the person and context before any ratna conversation. This is a cultural consultation, not a promise of a result.
Traditional association and gemological assessment remain distinct parts of a conversation. No material is presented as an outcome guarantee.
Read the consultation process →Individual assessment
Ask about a stone, setting or record.
Bring the object, report language or sourcing question you want to study. The next step is a direct conversation.
Begin a conversation