DigMyGem Gem encyclopedia

Persian Agate

Chalcedony & Agate Family

Persian agate is a geographic trade description for agate from Iran, not a distinct mineral variety. The material is banded chalcedony, made of microscopic intergrowths of quartz, and Iranian fields yield nodules in varied colors and patterns.

Identity

Material or variety
Agate (banded chalcedony)
Scientific or material identity
Agate (banded chalcedony)
Classification
Natural mineral or mineral variety
Composition or formula
SiO₂
Crystal system or structure
Aggregate or composite structure
Geological or manufacturing origin
Forms from silica- or mineral-rich fluids in cavities and fractures.
Mohs hardness
6.5 to 7
Specific gravity
2.58 to 2.64

Origins

Isfahan Province, Iran · South Khorasan Province, Iran · Sistan and Baluchestan Province, Iran · Zanjan Province, Iran

Appearance & optical properties

warm brown and ivory banded chalcedony.

History & discovery

Agate was described by Theophrastus in the fourth century BCE and named for the river Achates in Sicily. Iranian agate has several documented fields, including Khur in Isfahan Province, but “Persian agate” does not identify one fixed composition or pattern. It groups material by geographic origin instead.

Uses & care

Common uses
Iranian agate is cut into cabochons, beads, seals, small carvings, jewelry components, and polished slices that display its bands and contrasting colors.
Handling and cleaning
Clean with warm soapy water and a soft brush or cloth. Protect polished surfaces from hard blows and contact with harder gems, which can chip edges or leave scratches.

Jewellery

4 pieces of Persian Agate jewellery. Learners earn each one in DigMyGem by learning words; until then it shows as a silhouette.

  • Silhouette of Gonzaga Cameo

    Gonzaga Cameo

    Pendant

    A Hellenistic sardonyx cameo of two facing profiles cut through three layers of stone, long debated as Alexander and Olympias or Ptolemy and Arsinoe; once the pride of the Gonzaga collection, it is now in the State Hermitage Museum.

    Photograph of Gonzaga Cameo
    Photo: Sailko, CC BY-SA 3.0, via Wikimedia Commons
  • Silhouette of Blacas Cameo

    Blacas Cameo

    Jewel

    This unusually large Roman cameo is carved from a single banded agate and shows the emperor Augustus in profile wearing the aegis of Jupiter. It has been in the British Museum since 1867.

    Photograph of Blacas Cameo
    Photo: Marie-Lan Nguyen, Public domain, via Wikimedia Commons
  • Silhouette of Caravan Dawn Ring

    Caravan Dawn Ring

    Ring

    An imagined ring whose banded Persian agate recalls dunes at first light along an old caravan road.

  • Silhouette of Persian Signet Ring

    Persian Signet Ring

    Ring

    An imagined signet ring in the Persian tradition of carved agate seals, its flat reddish-brown stone engraved with a lion and sun.

Sources