Where is Ruby found?
Corundum (Al2O3) variety Ruby
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Open the appRuby occurs in specific geological environments. Knowing where to look, and in what kind of rock, is the difference between going home empty-handed and finding a great specimen.
Where to find Ruby
Mogok Valley, Myanmar (Burma)
Renowned for producing some of the finest 'pigeon's blood' rubies, primarily from marble-hosted deposits and associated placer deposits.
Mong Hsu, Myanmar
A significant source of rubies, often requiring heat treatment to improve color and clarity.
Thailand (Chanthaburi, Trat)
Historically a major source, particularly of darker, brownish-red rubies, often found in basalt-related deposits.
Sri Lanka (Ratnapura)
Known for producing rubies of various shades, often found in alluvial deposits alongside other gemstones.
Mozambique
A relatively new but highly significant source, producing a wide range of ruby qualities, often from primary metamorphic deposits and secondary placers.
Tanzania (Winza, Longido)
Produces rubies from both metamorphic and metasomatic deposits, sometimes with distinctive color zoning.
Vietnam (Luc Yen, Quy Chau)
Produces fine rubies from marble-hosted deposits, similar to those in Myanmar.
Collecting tips
- Look in Alluvial Deposits. Due to its high specific gravity and hardness, ruby often concentrates in riverbeds and ancient stream channels. Look for gravels containing other heavy minerals.
- Identify Associated Minerals. In primary deposits, ruby can be found with minerals like spinel, phlogopite mica, calcite, graphite, and various amphiboles or pyroxenes, depending on the host rock.
- Check for Fluorescence. Many natural rubies fluoresce red under long-wave UV light, which can help distinguish them from other red minerals. However, not all rubies fluoresce strongly, and some synthetics also fluoresce.
- Test Hardness. Ruby is very hard (9 on Mohs scale). It will scratch quartz (7) and topaz (8). This is a key diagnostic property, but should be done carefully on a non-gem quality part of the specimen.
- Observe Crystal Habit. Look for characteristic hexagonal crystal forms, often tabular or prismatic, which can be distinctive even in rough specimens.
Quick Check
- Color:
- Red (pinkish-red to deep red)
- Luster:
- Vitreous to adamantine
- Streak:
- White
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