Copal: properties, varieties and value factors

Key properties

Chemical formula	Organic resin — diterpenoid and triterpenoid hydrocarbons (no succinic acid)
Crystal system	Amorphous (none — organic)
Mohs hardness	2
Toughness	Fair (surface crazes with age)
Refractive index	1.530-1.540
Optic character	Isotropic (SR); anomalous double refraction common
Specific gravity	1.03-1.10
Cleavage	None
Fracture	Conchoidal to uneven
Habit	Lumps, tears and flows of resin, often still glossy-skinned; no crystal form
Lustre	Resinous; polish: Resinous to vitreous
UV fluorescence	Whiter and often stronger than amber — inert to strong bluish white under SW, weaker under LW
Pleochroism	None
Cause of colour	Yellow to brown from the resin's own terpenoid compounds and early oxidative ageing
Typical inclusions	Abundant modern insects and plant debris (a tell-tale of immaturity — often still-bright captures), bubbles, surface crazing
Stability	Burns readily; dissolves or swells in acetone, ether, alcohols and turpentine; darkens and crazes with age and light
Heat sensitivity	Extreme — softens and ignites easily; never steam or ultrasonic
Care and cleaning	Dry soft cloth only for routine care; if needed a quick cool soapy rinse and immediate drying; absolutely no solvents, alcohol wipes, perfume, ultrasonic or steam
Birthstones	None
Availability	Common where sourced (Colombia, Madagascar, East Africa, New Zealand) but scarce in mainstream Western jewellery; abundant in tourist and insect-specimen trade
Recognition	Looks like amber but is acetone-soluble within seconds, often fluoresces whiter under SW, commonly shows fresh surface crazing; RI 1.53-1.54, SG about 1.06

Varieties

Copal

Colour	pale yellow to orange and brown
Transparency	variable
Clarity type	No formal type — transparent to translucent; milky swirls and insect inclusions typical
Phenomena	None
Appearance	Fresh, glassy yellow to orange resin, often with glossy original surface skins, milky swirls and very modern-looking insects, leaves and even air bubbles trapped intact; crazes into a checkered surface as it ages
Trade names	Kauri gum (New Zealand Agathis resin) • Colombian copal • 'young amber'
Misnomers	Amber (routine mis-selling) • 'Colombian amber' for young copal • 'Madagascar amber' for recent copal with insects
Typical sizes	Lumps from a few carats to several hundred carats; beads 6-20 mm; insect pieces sold whole
Cutting styles	Beads • tumbled pieces • polished natural lumps • insect specimens left whole or cut into small windows
Key separations	vs amber: acetone drop — copal goes tacky within 2-3 seconds, amber is unaffected or only slightly attacked after the same time; ether swells copal; copal often whiter SW fluorescence; copal inclusions may be modern species, amber's are extinct; copal crazes on the surface • vs plastic: hot point — copal smells resinous like amber-family, plastics acrid; plastics have uniform moulded shapes • vs glass: heft and hot point
Sources (localities)	Colombia (Andes foothills — most copal mis-sold as amber) • Madagascar (abundant insect copal) • New Zealand (kauri gum, Agathis australis — historic trade) • East Africa (Kenya, Tanzania) • Mexico and Central America (ceremonial copal) • Indonesia and Philippines • Brazil
Availability	Cheap and abundant at source; scarce in legitimate Western jewellery outlets because it must be labelled copal
Market notes	The value gap drives persistent fraud: copal with insects sold as 'amber' at amber prices. Disclosure resolves it — copal is honest material honestly named
Care notes	Treat as more fragile than amber: no solvents of any kind (including hand sanitiser), no heat, no prolonged sun; store cool and stable
In short	Copal is amber's younger sibling — same look, same insects, none of the geological maturity. The acetone test unmasks it in seconds, which is why it remains the classic deliberate fraud and the classic teaching case.

Size (ct)	USD per carat	Tier	As of
1.00–50.00	$0.10 – $1.00	commercial beads, tumbles and insect pieces	2026-10-26

Retail market survey, per carat unless noted. Ranges describe what commercial to fine stones trade at; exceptional stones and provenance premiums sit above them.

Sources

GIA gem encyclopedia · mindat.org · Wikipedia

Data compiled and fact-checked against gemmological literature, October 2026 (JDMIS gem reference). Properties are ranges accepted in gemmological practice; individual stones vary.

Key properties

Varieties

Copal

Sources

See also