Onyx

Parallel-banded chalcedony. Uniform black onyx in jewellery is frequently treated to produce its colour.

Composition: SiO2
Hardness: 6.5–7 on the Mohs scale · scratch resistance, not toughness
Birthstone: No modern month assignment
Care: Clean gently with a soft cloth and mild soapy water; rinse briefly and dry. Avoid heat, chemicals, ultrasonic cleaning and hard impacts. Ask about treatments before cleaning.
Paired with: Capricorn · Snake years · Water element
Symbolic: Grounding, Confidence · Root chakra. Design vocabulary, not a physical effect.

Mineral reference ↗

Pairs well with

Stones that share its meaning.

Garnet

Garnet group · Mohs 6.5–7.5

Grounding · Confidence

Bloodstone

Chalcedony · Mohs 6.5–7

Grounding · Confidence

Ruby

Corundum · Mohs 9

Confidence · Connection

Peridot

Olivine · Mohs 6.5–7

Confidence · Connection

Gem properties describe materials. Chakra and intention pairings are symbolic traditions and Mulu design choices, not measured energy or medical effects. Stones are not proven to treat disease or improve sleep.