Gems by Size
Gemstone types grouped by typical size
VERY LARGE STONES (50+ carats)
| Gem Type | Typical Size | Investment Tier |
|---|---|---|
| Kunzite | 1-100+ carats (commercial: 5-50 carats; very large clean crystals available) | BEARISH |
| Amethyst | 1-100+ carats (commercial: 5-50 carats; large clean stones available) | VERY BEARISH |
| Citrine | 1-100+ carats (commercial: 5-50 carats; large stones available) | VERY BEARISH |
| Rose Quartz | 1-100+ carats (commercial: 5-50 carats; massive material common) | VERY BEARISH |
| Smoky Quartz | 1-100+ carats (commercial: 5-50 carats; large crystals available) | VERY BEARISH |
| Milky Quartz | 1-100+ carats (commercial: any size available) | VERY BEARISH |
| Rock Crystal | 1-100+ carats (commercial: any size available) | VERY BEARISH |
| Aventurine | 1-100+ carats (commercial: any size for carvings) | VERY BEARISH |
| Tiger's Eye | 1-100+ carats (commercial: any size for cabochons) | VERY BEARISH |
| Chalcedony | 1-100+ carats (commercial: any size for cabochons) | VERY BEARISH |
| Agate | 1-100+ carats (commercial: any size for cabochons and slabs) | VERY BEARISH |
| Carnelian | 1-100+ carats (commercial: any size for cabochons) | VERY BEARISH |
| Onyx | 1-100+ carats (commercial: any size for cabochons) | VERY BEARISH |
| Sardonyx | 1-100+ carats (commercial: any size for cabochons) | VERY BEARISH |
| Jasper | 1-100+ carats (commercial: any size for cabochons) | VERY BEARISH |
| Jadeite | 1-100+ carats (commercial: any size for carvings) | NEUTRAL+ |
| Nephrite | 1-100+ carats (commercial: any size for carvings) | BEARISH |
| Lapis Lazuli | 1-100+ carats (commercial: any size for cabochons and carvings) | BEARISH |
| Malachite | 1-100+ carats (commercial: any size for cabochons and carvings) | VERY BEARISH |
| Sodalite | 1-100+ carats (commercial: any size for cabochons) | VERY BEARISH |
| Quartz | 1-100+ carats (commercial: any size available) | VERY BEARISH |
| Serpentine | 1-100+ carats (commercial: any size for carvings and cabochons) | VERY BEARISH |
| Topaz | 1-100+ carats (commercial: 2-30 carats; large stones common) | VERY BEARISH |
| Blue Topaz | 1-100+ carats (commercial: 5-50 carats; large clean stones readily available) | BEARISH |
| Hematite | 1-100+ carats (commercial: any size for cabochons and carvings) | VERY BEARISH |
| Calcite | 1-100+ carats (commercial: any size available) | VERY BEARISH |
| Synthetic Sapphire | 1-100+ carats (commercial: any size available) | VERY BEARISH |
| Synthetic Ruby | 1-100+ carats (commercial: any size available) | VERY BEARISH |
| Synthetic Emerald | 1-100+ carats (commercial: any size available) | VERY BEARISH |
| Diamond | 0.01-100+ carats (commercial: 0.25-5 carats; exceptional stones can exceed 100 carats) | NEUTRAL+ |
LARGE STONES (20-50 carats)
| Gem Type | Typical Size | Investment Tier |
|---|---|---|
| Aquamarine | 1-50+ carats (commercial: 5-30 carats; large clean stones relatively available) | BEARISH |
| Morganite | 1-50+ carats (commercial: 5-30 carats; large clean stones available) | BEARISH |
| Goshenite | 1-50 carats (commercial: 5-20 carats; clean crystals available) | BEARISH |
| Star Sapphire | 1-50+ carats (commercial: 3-20 carats; larger stones with good stars available) | VERY BULLISH |
| Labradorite | 1-50+ carats (commercial: 5-30 carats; larger stones available) | BEARISH |
| Amazonite | 1-50+ carats (commercial: 5-30 carats; larger stones available) | VERY BEARISH |
| Boulder Opal | 1-50+ carats (commercial: 5-20 carats; often sold as specimens) | BEARISH |
| Ametrine | 1-50 carats (commercial: 3-20 carats; medium to large sizes) | NEUTRAL |
| Prasiolite | 1-50 carats (commercial: 3-20 carats; medium sizes common) | BEARISH |
| Rutilated Quartz | 1-50 carats (commercial: 3-20 carats; larger stones available) | BEARISH |
| Tourmalinated Quartz | 1-50 carats (commercial: 3-20 carats; larger stones available) | BEARISH |
| Hawk's Eye | 1-50 carats (commercial: 3-20 carats; cabochons) | BEARISH |
| Chrysoprase | 1-50 carats (commercial: 3-20 carats; cabochons) | NEUTRAL |
| Bloodstone | 1-50 carats (commercial: 3-20 carats; cabochons) | VERY BEARISH |
| Seraphinite | 1-50 carats (commercial: 5-20 carats; cabochons) | BEARISH |
| Charoite | 1-50 carats (commercial: 5-20 carats; cabochons) | NEUTRAL+ |
| Turquoise | 1-50+ carats (commercial: any size for cabochons) | BEARISH |
| Rhodonite | 1-50 carats (commercial: 5-20 carats; cabochons) | VERY BEARISH |
| Fluorite | 1-50 carats (commercial: 5-20 carats; collector cuts) | VERY BEARISH |
| Aragonite | 1-50+ carats (commercial: any size for specimens and cabochons) | VERY BEARISH |
| Tantalite | 1-50+ carats (commercial: 5-30 carats; typically sold as specimens) | NEUTRAL |
| Spodumene | 1-50+ carats (commercial: 3-20 carats; large clean crystals available) | BEARISH |
| Feldspar | 1-50+ carats (commercial: 3-20 carats; larger stones available) | VERY BEARISH |
| Sapphire | 0.5-50+ carats (commercial: 1-10 carats; large fine stones available but expensive) | VERY BULLISH |
| Tanzanite | 0.5-50+ carats (commercial: 1-15 carats; large clean stones available but expensive) | BULLISH |
| Tourmaline | 0.5-50+ carats (commercial: 1-20 carats; large stones available) | VERY BEARISH |
| Opal | 0.5-50+ carats (commercial: 1-15 carats; various sizes) | BEARISH |
| Elbaite | 0.5-50+ carats (commercial: 1-20 carats; large crystals available) | NEUTRAL |
MEDIUM TO LARGE STONES (10-30 carats)
| Gem Type | Typical Size | Investment Tier |
|---|---|---|
| Heliodor | 1-30 carats (commercial: 3-15 carats; medium sizes most common) | BEARISH |
| Green Beryl | 1-30 carats (commercial: 3-15 carats; medium sizes available) | BEARISH |
| Star Ruby | 1-30 carats (commercial: 2-15 carats; fine stars in larger sizes rare) | BULLISH |
| Moonstone | 1-30 carats (commercial: 2-15 carats; larger stones with good adularescence available) | BEARISH |
| Sunstone | 1-30 carats (commercial: 3-15 carats; larger stones available) | BEARISH |
| Peruvian Opal | 1-30 carats (commercial: 3-15 carats; larger stones available) | BEARISH |
| Almandine | 1-30 carats (commercial: 2-15 carats; larger stones available) | VERY BEARISH |
| Sugilite | 1-30 carats (commercial: 3-15 carats; cabochons) | NEUTRAL+ |
| Larimar | 1-30 carats (commercial: 3-15 carats; cabochons) | NEUTRAL+ |
| Azurite | 1-30 carats (commercial: 3-15 carats; cabochons) | BEARISH |
| Prehnite | 1-30 carats (commercial: 3-15 carats; cabochons and faceted) | VERY BEARISH |
| Danburite | 1-30 carats (commercial: 2-15 carats; larger clean stones available) | Unknown |
| Scheelite | 1-30+ carats (commercial: 2-15 carats; larger stones available) | Unknown |
| Opaque Emerald | 1-30 carats (commercial: 2-15 carats; larger stones available) | NEUTRAL+ |
| Smithsonite | 1-30 carats (commercial: 3-15 carats; cabochons) | Unknown |
| Albite | 1-30 carats (commercial: 3-15 carats; medium sizes) | BEARISH |
| Vesuvianite | 1-30 carats (commercial: 3-15 carats; larger stones available) | BEARISH |
| Zoisite | 1-30 carats (commercial: 3-15 carats; larger stones available) | BEARISH |
| Moldavite | 1-30 carats (commercial: 3-15 carats; irregular shapes) | NEUTRAL+ |
| Beryl | 1-30 carats (commercial: 2-15 carats; larger stones available) | NEUTRAL+ |
| Idocrase | 1-30 carats (commercial: 3-15 carats; larger stones available) | BEARISH |
| Imperial Topaz | 0.5-30 carats (commercial: 1-10 carats; fine color over 10 carats is rare) | BULLISH |
| Rubellite | 0.5-30 carats (commercial: 1-15 carats; clean stones in larger sizes available) | NEUTRAL |
| Verdelite | 0.5-30 carats (commercial: 1-15 carats; large clean stones available) | NEUTRAL |
| Garnet | 0.5-30 carats (commercial: 1-15 carats; various sizes) | VERY BEARISH |
| Achroite | 0.5-30 carats (commercial: 1-15 carats; larger clean stones available) | Unknown |
| Brown Diamond | 0.25-30 carats (commercial: 0.5-10 carats; larger stones more available) | NEUTRAL+ |
| Andalusite | 1-20 carats (commercial: 2-10 carats; medium sizes most common) | NEUTRAL |
| Orthoclase | 1-20 carats (commercial: 2-10 carats; medium sizes most common) | BEARISH |
| Oligoclase | 1-20 carats (commercial: 2-10 carats; medium sizes) | BEARISH |
| Fire Opal | 1-20 carats (commercial: 2-10 carats; larger stones available) | BEARISH |
| White Opal | 1-20 carats (commercial: 2-10 carats; larger stones available) | BEARISH |
| Zircon | 1-20 carats (commercial: 2-10 carats; larger stones available) | BEARISH |
| Rhodolite | 1-20 carats (commercial: 2-10 carats; larger stones available) | BEARISH |
| Grossular | 1-20 carats (commercial: 2-10 carats; medium sizes) | BEARISH |
| Rhodochrosite | 1-20 carats (commercial: 2-10 carats; transparent material rare) | NEUTRAL+ |
| Iolite | 1-20 carats (commercial: 2-10 carats; larger stones available) | BEARISH |
| Scapolite | 1-20 carats (commercial: 2-10 carats; medium sizes) | BEARISH |
| Bastnasite | 1-20+ carats (commercial: 2-10 carats; typically sold as specimens) | BEARISH |
| Amblygonite | 1-20 carats (commercial: 2-10 carats; medium sizes available) | Unknown |
| Bytownite | 1-20 carats (commercial: 2-10 carats; medium sizes) | BEARISH |
| Petalite | 1-20 carats (commercial: 2-10 carats; larger stones available) | Unknown |
| Epidote | 1-20 carats (commercial: 2-10 carats; medium sizes) | Unknown |
| Sillimanite | 1-20 carats (commercial: 2-10 carats; clean stones rare) | Unknown |
| Triplite | 1-20 carats (commercial: 2-10 carats; medium sizes) | Unknown |
| Red Spinel | 0.5-20 carats (commercial: 1-8 carats; fine stones over 10 carats are rare) | VERY BULLISH |
| Pink Spinel | 0.5-20 carats (commercial: 1-10 carats; larger sizes more available than red) | NEUTRAL+ |
| Pink Topaz | 0.5-20 carats (commercial: 1-8 carats; natural pink in larger sizes is rare) | NEUTRAL+ |
| Sphene | 0.5-20 carats (commercial: 1-8 carats; larger clean stones are uncommon) | NEUTRAL+ |
| Indicolite | 0.5-20 carats (commercial: 1-10 carats; larger clean stones uncommon) | NEUTRAL |
| Sphalerite | 0.5-20 carats (commercial: 1-8 carats; fragility limits cutting of large stones) | NEUTRAL |
| Hiddenite | 0.5-20 carats (commercial: 1-8 carats; larger stones less common than kunzite) | NEUTRAL |
| Watermelon Tourmaline | 0.5-20 carats (commercial: 1-10 carats; typically cut as slices) | NEUTRAL |
| Cat's Eye Chrysoberyl | 0.5-20 carats (commercial: 1-10 carats; fine eyes in larger sizes rare) | BULLISH |
| Black Opal | 0.5-20 carats (commercial: 1-10 carats; large stones with good play of color rare) | VERY BULLISH |
| Peridot | 0.5-20 carats (commercial: 1-10 carats; larger clean stones less common) | BEARISH |
| Phenakite | 0.5-20 carats (commercial: 1-10 carats; clean stones over 10 carats rare) | BULLISH |
| Spinel | 0.5-20 carats (commercial: 1-10 carats; larger stones available) | NEUTRAL+ |
| Chrysoberyl | 0.5-20 carats (commercial: 1-10 carats; larger stones available) | NEUTRAL+ |
| Cassiterite | 0.5-20+ carats (commercial: 1-10 carats; faceted gems typically smaller) | Unknown |
| Ammolite | 0.5-20 carats | Unknown |
| Lepidolite | 0.5-20 carats | Unknown |
| Emerald | 0.25-20 carats (commercial: 0.5-5 carats; clean stones over 10 carats are rare) | VERY BULLISH |
| Ruby | 0.25-20 carats (commercial: 0.5-5 carats; fine quality stones over 10 carats are extremely rare) | VERY BULLISH |
| Black Diamond | 0.25-20 carats (commercial: 0.5-5 carats; larger stones available but expensive) | BULLISH |
| Yellow Diamond | 0.25-20 carats (commercial: 0.5-5 carats; larger stones available) | VERY BULLISH |
SMALL TO MEDIUM STONES (under 10 carats)
| Gem Type | Typical Size | Investment Tier |
|---|---|---|
| Andesine | 1-15 carats (commercial: 2-8 carats; medium sizes most common) | BEARISH |
| Jelly Opal | 1-15 carats (commercial: 2-8 carats; medium sizes) | BEARISH |
| Pyrope | 1-15 carats (commercial: 1-8 carats; larger stones less common) | BEARISH |
| Spessartite | 1-15 carats (commercial: 1-8 carats; larger clean stones rare) | NEUTRAL+ |
| Kyanite | 1-15 carats (commercial: 2-8 carats; clean stones less common) | BEARISH |
| Apatite | 1-15 carats (commercial: 2-8 carats; medium sizes) | BEARISH |
| Diopside | 1-15 carats (commercial: 2-8 carats; medium sizes) | BEARISH |
| Hypersthene | 1-15 carats (commercial: 2-8 carats; cabochons) | BEARISH |
| Erythrite | 1-15+ carats (commercial: 2-8 carats; typically sold as specimens) | BEARISH |
| Pollucite | 1-15 carats (commercial: 2-8 carats; transparent stones rare) | Unknown |
| Blue Spinel | 0.5-15 carats (commercial: 1-5 carats; cobalt blue typically smaller, over 5 carats rare) | BULLISH |
| Crystal Opal | 0.5-15 carats (commercial: 1-8 carats; medium sizes most common) | NEUTRAL |
| Burmese Spinel | 0.5-15 carats (commercial: 1-8 carats; larger fine stones rare) | BULLISH |
| Tanzanian Spinel | 0.5-15 carats (commercial: 1-8 carats; larger stones available) | BULLISH |
| Hackmanite | 0.5-15 carats (commercial: 1-8 carats; larger clean stones rare) | Unknown |
| Malaya Garnet | 0.5-15 carats (commercial: 1-8 carats; larger clean stones available) | NEUTRAL+ |
| Cerussite | 0.5-15 carats (commercial: 1-8 carats; faceted gems for collectors) | Unknown |
| Brazilianite | 0.5-15 carats (commercial: 1-8 carats; clean stones over 5ct rare) | Unknown |
| Axinite | 0.5-15 carats (commercial: 1-8 carats; clean stones over 5ct rare) | Unknown |
| Hambergite | 0.5-15 carats (commercial: 1-8 carats; clean stones rare) | Unknown |
| Herderite | 0.5-15 carats (commercial: 1-8 carats; clean stones rare) | Unknown |
| Afghanite | 1-10 carats (commercial: 2-5 carats; rare collector stone) | NEUTRAL+ |
| Hyalite | 1-10 carats (commercial: 2-5 carats; typically small) | BEARISH |
| Mali Garnet | 1-10 carats (commercial: 1-5 carats; larger stones rare) | NEUTRAL |
| Enstatite | 1-10 carats (commercial: 1-5 carats; smaller sizes) | BEARISH |
| Padparadscha Sapphire | 0.5-10 carats (commercial: 1-5 carats; fine stones over 5 carats are rare) | VERY BULLISH |
| Diaspore | 0.5-10 carats (commercial: 1-5 carats; color-change varieties typically smaller) | NEUTRAL |
| Andradite | 0.5-10 carats (commercial: 1-5 carats; most varieties in smaller sizes) | NEUTRAL |
| Color-Change Garnet | 0.5-10 carats (commercial: 1-5 carats; larger stones rare) | BULLISH |
| Kornerupine | 0.5-10 carats (commercial: 1-5 carats; larger stones rare) | NEUTRAL+ |
| Vietnamese Purple Spinel | 0.5-10 carats (commercial: 1-5 carats; larger stones rare and valuable) | BULLISH |
| Xenotime | 0.5-10+ carats (commercial: 1-5 carats; typically sold as specimens) | NEUTRAL |
| Mahenge Spinel | 0.5-10 carats (commercial: 1-5 carats; larger stones increasingly rare) | BULLISH |
| Chrome Sphene | 0.5-10 carats (commercial: 1-5 carats; larger clean stones rare) | Unknown |
| Opaque Hauyne | 0.5-10 carats (commercial: 1-5 carats; larger stones rare) | Unknown |
| Cuprite | 0.5-10 carats (commercial: 1-5 carats; transparent stones rare) | Unknown |
| Phosphophyllite | 0.5-10 carats (commercial: 1-5 carats; extremely fragile) | Unknown |
| Dioptase | 0.5-10 carats (commercial: 1-5 carats; faceted gems rare) | Unknown |
| Euclase | 0.5-10 carats (commercial: 1-5 carats; larger stones very rare) | BULLISH |
| Sapphirine | 0.5-10 carats (commercial: 1-5 carats; faceted gems very rare) | BULLISH |
| Pargasite | 0.5-10 carats (commercial: 1-5 carats; clean stones rare) | Unknown |
| Parisite | 0.5-10 carats (commercial: 1-5 carats; faceted gems rare) | Unknown |
| Chondrodite | 0.5-10 carats (commercial: 1-5 carats; clean stones rare) | Unknown |
| Stibiotantalite | 0.5-10 carats (commercial: 1-5 carats; faceted gems very rare) | NEUTRAL+ |
| Alexandrite | 0.25-10 carats (commercial: 0.5-3 carats; stones over 5 carats with strong change are very rare) | VERY BULLISH |
| Tsavorite | 0.25-10 carats (commercial: 0.5-3 carats; clean stones over 5 carats are rare) | BULLISH |
| Paraiba Tourmaline | 0.1-10 carats (commercial: 0.25-3 carats; stones over 5 carats are exceptionally rare) | VERY BULLISH |
VERY SMALL STONES (typically under 3 carats)
| Gem Type | Typical Size | Investment Tier |
|---|---|---|
| Clinohumite | 0.5-5 carats (commercial: 1-3 carats; rare, typically small sizes) | BULLISH |
| Demantoid | 0.25-5 carats (commercial: 0.5-2 carats; stones over 3 carats are very rare) | BULLISH |
| Taaffeite | 0.1-5 carats (commercial: 0.25-2 carats; most stones under 2 carats) | VERY BULLISH |
| Grandidierite | 0.1-5 carats (commercial: 0.25-2 carats; faceted stones over 3 carats are rare) | BULLISH |
| Benitoite | 0.1-5 carats (commercial: 0.25-2 carats; stones over 2 carats are very rare) | BULLISH |
| Jeremejevite | 0.1-5 carats (commercial: 0.25-2 carats; museum-quality stones typically under 3 carats) | BULLISH |
| Pink Diamond | 0.1-5 carats (commercial: 0.25-2 carats; stones over 1 carat extremely rare) | VERY BULLISH |
| Pezzottaite | 0.1-5 carats (commercial: 0.25-2 carats; stones over 2 carats very rare) | VERY BULLISH |
| Green Diamond | 0.1-5 carats (commercial: 0.25-2 carats; stones over 1 carat extremely rare) | VERY BULLISH |
| Blue Diamond | 0.1-5 carats (commercial: 0.25-2 carats; stones over 1 carat extremely rare) | VERY BULLISH |
| Musgravite | 0.1-3 carats (commercial: 0.25-1 carat; extremely rare in any size) | VERY BULLISH |
| Painite | 0.1-3 carats (commercial: 0.25-1 carat; extremely rare in any size) | VERY BULLISH |
| Serendibite | 0.1-3 carats (commercial: 0.25-1 carat; exceptionally rare, most under 2 carats) | BULLISH |
| Hauyne | 0.1-3 carats (commercial: 0.2-1 carats; stones over 1 carat extremely rare) | BULLISH |
| Poudretteite | 0.1-3 carats (commercial: 0.1-1 carats; stones over 1 carat extremely rare) | VERY BULLISH |
| Bixbite | 0.1-2 carats (commercial: 0.25-1 carat; stones over 2 carats are exceptionally rare) | BULLISH |
| Vayrynenite | 0.1-2 carats (commercial: 0.25-1 carat; extremely rare, very small sizes) | BULLISH |
| Uvarovite | 0.1-2 carats (commercial: typically druzy crystals) | NEUTRAL |