Write the formula for erbium(III) oxide, the pink ceramic pigment.
Er3+ with O2- crosses to Er2O3 — the same M2O3 template that runs from Sc2O3 to Lu2O3 across every +3 rare earth.
What Is the Charge of Erbium?
Erbium commonly forms Er3+ in introductory ionic compounds.
Erbium is Er3+ — rose-pink salts, Er2O3 that tints 'pink gold' ceramics — and one modern superpower: doped into optical fiber, Er3+ amplifies the 1550 nm light that carries intercontinental internet traffic.
| Element | Erbium |
|---|---|
| Symbol | Er |
| Atomic number | 68 |
| Common ionic charge | +3 |
| Common ions | Er3+ |
Visual reference
Erbium element image and atomic model
Images are used as visual references; charge rules still depend on the compound.
The electron story behind Erbium's charge
Erbium is [Xe]4f12 6s2; the lanthanide +3 gives Er3+ (f11). Its claim to fame is an f-electron energy gap that exactly matches telecom photons — a coincidence of quantum levels, available only because the 3+ ion's f electrons sit shielded and sharp.
This is a classroom reference range, not an exhaustive list of all oxidation states.
The assumption that trips people up on Erbium
Assuming signal amplification means electronics. An erbium-doped fiber amplifier is purely optical: pump light excites Er3+ ions, and passing data photons stimulate them to emit in step — no conversion to electrical signals, no transistors, just charged ions lasing gently inside glass.
Worked example: Er in a formula problem
Er3+ in real compounds
ErCl3
Erbium chloride
Er3+ balances chloride ions.
Er2O3
Erbium oxide
Erbium can form oxides where total positive and negative charge balances.
Questions students ask about erbium
Why 1550 nm — what's special about that wavelength?
Silica fiber loses least light there, and Er3+ happens to amplify exactly there. That match — geology's glass meeting a lanthanide's f levels — is why undersea cables need repeater amplifiers only every ~80 km.
Where else does Er3+'s light matter?
Er:YAG lasers at 2.94 µm are dentistry and dermatology workhorses — water absorbs that wavelength even more fiercely, enabling precise ablation of enamel and skin.
Is pink gold colored by erbium?
Jewelry 'rose gold' is copper alloying; but erbium oxide genuinely pinks glass and cubic zirconia. If a pink gem's tint survives any lighting, a rare-earth 3+ ion may be responsible.
How do I use this charge in formulas?
Combine positive and negative ions so the total charge is zero — or let the ionic compound calculator do the crossing for you. The full chart lives on the periodic table with charges.
Where this data comes from
Charges and element facts on this page are checked against the primary references below. Found an error? Email hello@periodictablewithcharges.com — corrections ship in the next content update. See how this site is edited.