Skip to Main Content

About Tellurium

Tellurium Bohr

Tellurium was discovered in Franz Joseph Muller in 1782 when he isolated it as a trace component from a sample of gold ore. He initially believed his find to be antimony, but eventually realized its properties did not match any known element and reported his findings to other chemists. In 1798, Martin Heinrich Klaproth completed further tests to confirm that a new element had in fact been discovered, and named it “tellurium”, meaning “earth.”

Tellurium is a brittle, silver-white, semiconducting metalloid that also exhibits mild photoconductivity. One of the largest uses for tellurium are in semiconducting compound materials that exploit its unique electrical properties. Cadmium telluride is particularly well known as the basis for a type of thin film solar cell that can be manufactured with relatively little impact on the environment and used in some installations at a comparable cost to traditional silicon cells. Cadmium zinc telluride is likewise used in solar cells, as well as in radiation detectors, terahertz wave generation and detection devices, electro-optic modulators, solid-state x-ray detectors, and photoreactive gratings. When tellurium is added as a dopant to zinc selenide, the resultant material is a scintillator material used in x-ray and gamma ray detectors. Bismuth telluride and lead telluride are both thermoelectric materials used in thermoelectric refrigeration and in portable thermal generators. Additionally, tellurium’s photoconductivity once lent it to use along with the similar element selenium in photocopiers, however modern photocopiers use organic photoconductors in place of these elements.

Tellurium also plays a significant role in technology in the form of chalcogenide glasses. These glasses, made using sulfur, selenium, or tellurium compounds, exhibit high refractive indices and non-linear optical effects, and are frequently used in optical fibers for telecommunications, lasers, photonic integrated circuits, and other optical applications. Additionally, some chalcogenide glasses including GeSbTe and AgInSbTe undergo predictable changes in crystal structure driven by thermal energy, and this property is exploited in rewritable optical disks and phase-change computer memory.

Another major use of tellurium is as an additive to metal alloys. It is used primarily to improve the machinability of steel or copper, and to improve strength and durability of lead. It is also found in some forms of cast iron. Additionally, telluride compounds may be used as pigments to color ceramics, as components of blasting caps, or as catalysts for some industrial chemical processes.

Tellurium is a relatively rare element, and is produced commercially mostly from byproducts of electrolytic copper refining. Tellurium is also occasionally recovered from old devices which contained it, most often outdated photocopiers.

+ Open All
- Close All
Semiconductor & Optical
Sputtering Targets

Tellurium is a p-type semiconductor, and shows greater conductivity in certain directions, depending on alignment of the atoms. Many tellurium compounds exhibit photoconductivity--their conductivity increases slightly with exposure to light--which makes many tellurides candidates for solar energy applications. Tellurium improves the machinability of copper and stainless steel, and its addition to lead improves its strength and hardness. High Purity (99.999%) Tellurium Oxide (TeO2) PowderTellurium is used as a basic ingredient in blasting caps, and is added to cast iron for chill control. Tellurium is used in ceramics. Bismuth telluride has been used in thermoelectric devices. High Purity (99.99999%) Tellurium (Te) Sputtering TargetTellurium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Tellurium oxides are available in powder and dense pellet form for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Tellurium fluoride is another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Tellurium is also available in soluble forms including chlorides and nitrates. These compounds can be manufactured as solutions at specified stoichiometries.

Tellurium Properties

Tellurium (Te) atomic and molecular weight, atomic number and elemental symbolTellurium is a Block P, Group 16, Period 5 element. The number of electrons in each of Tellurium's shells is 2, 8, 18, 18, 6 and its electron configuration isTellurium Bohr Model[Kr] 4d10 5s2 5p4. In its elemental form tellurium's CAS number is 13494-80-9. The tellurium atom has a radius of and its Van der Waals radius is Tellurium is most commonly sourced from the anode sludges produced as a byproduct of copper refining. Elemental Tellurium Tellurium was first discovered by Franz Muller von Reichenstein in 1782. The name Tellurium originates from the Greek word 'Tellus' meaning Earth.

Symbol: Te
Atomic Number: 52
Atomic Weight: 127.6
Element Category: metalloid
Group, Period, Block: 16 (chalcogens), 5, p
Color: silvery lustrous gray/ silvery
Other Names: Tellur, Telúrio
Melting Point: 449.51°C, 841.118°F, 722.66 K
Boiling Point: 988°C, 1810.4°F, 1261.15 K
Density: 6247 kg·m3
Liquid Density @ Melting Point: 5.70 g·cm3
Density @ 20°C: 6.24 g/cm3
Density of Solid: 6240 kg·m3
Specific Heat: 0.0481 Cal/g/K @ 25°C
Superconductivity Temperature: N/A
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): 13.5
Heat of Vaporization (kJ·mol-1): 104.6
Heat of Atomization (kJ·mol-1): 197
Thermal Conductivity: (1.97–3.38) W·m-1·K-1
Thermal Expansion: N/A
Electrical Resistivity: 4.36x10(5) nΩ-cm @ 25°C
Tensile Strength: N/A
Molar Heat Capacity: 25.73 J·mol-1·K-1
Young's Modulus: 43 GPa
Shear Modulus: 16 GPa
Bulk Modulus: 65 GPa
Poisson Ratio: N/A
Mohs Hardness: 2.25
Vickers Hardness: N/A
Brinell Hardness: 180 MPa
Speed of Sound: (20 °C) 2610 m·s-1
Pauling Electronegativity: 2.1
Sanderson Electronegativity: 2.62
Allred Rochow Electronegativity: 2.01
Mulliken-Jaffe Electronegativity: 2.41 (16.7% s orbital)
Allen Electronegativity: 2.158
Pauling Electropositivity: 1.9
Reflectivity (%): 50
Refractive Index: 1.000991
Electrons: 52
Protons: 52
Neutrons: 76
Electron Configuration: [Kr] 4d10 5s2 5p4
Atomic Radius: 140 pm
Atomic Radius,
non-bonded (Å):
Covalent Radius: 138±4 pm
Covalent Radius (Å): 1.37
Van der Waals Radius: 206 pm
Oxidation States: 6, 4, -2
Phase: Solid
Crystal Structure: hexagonal
Magnetic Ordering: diamagnetic
Electron Affinity (kJ·mol-1) 190.173
1st Ionization Energy: 869.3 kJ·mol-1
2nd Ionization Energy: 1794.64 kJ·mol-1
3rd Ionization Energy: 2697.75 kJ·mol-1
CAS Number: 13494-80-9
EC Number: 236-813-4
MDL Number: MFCD00134062
Beilstein Number: N/A
SMILES Identifier: [Te]
InChI Identifier: InChI=1S/Te
PubChem CID: 6327182
ChemSpider ID: 4885717
Earth - Total: 1490 ppb 
Mercury - Total: 122 ppb
Venus - Total: 830 ppb
Earth - Seawater (Oceans), ppb by weight: N/A
Earth - Seawater (Oceans), ppb by atoms: N/A
Earth -  Crust (Crustal Rocks), ppb by weight: 1
Earth -  Crust (Crustal Rocks), ppb by atoms: 0.2
Sun - Total, ppb by weight: N/A
Sun - Total, ppb by atoms: N/A
Stream, ppb by weight: N/A
Stream, ppb by atoms: N/A
Meterorite (Carbonaceous), ppb by weight: 2100
Meterorite (Carbonaceous), ppb by atoms: 300
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: 9
Universe, ppb by atom: 0.09
Discovered By: Franz-Joseph Müller von Reichenstein
Discovery Date: 1782
First Isolation: Martin Heinrich Klaproth

Health, Safety & Transportation Information for Tellurium

Safety data for Tellurium and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental Tellurium.

Safety Data
Signal Word Danger
Hazard Statements H301
Hazard Codes T
Risk Codes 25
Safety Precautions 45
RTECS Number WY2625000
Transport Information UN 3288 6.1/PG 3
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)
Skull and Crossbones-Acute Toxicity
Review and Print SDS for Elemental Tellurium


Date Created: 05/15/2015
Date Revised: 05/15/2015


Product Name: Tellurium Metal

Product Number: All applicable American Elements product codes, e.g. TE-E-02, TE-E-03, TE-E-04, TE-E-05, TE-E-06, TE-E-07

CAS #: 13494-80-9

Relevant identified uses of the substance: Scientific research and development

Supplier details:
American Elements
1093 Broxton Ave. Suite 2000
Los Angeles, CA 90024
Tel: +1 310-208-0551
Fax: +1 310-208-0351

Emergency telephone number:
Domestic, North America +1 800-424-9300
International +1 703-527-3887


Classification of the substance or mixture
Classification according to Regulation (EC) No 1272/2008
GHS06 Skull and crossbones
Acute Tox. 3 H301 Toxic if swallowed.
Acute Tox. 4 H332 Harmful if inhaled.
Hazards not otherwise classified
No information known.
Label elements
Labelling according to Regulation (EC) No 1272/2008
The substance is classified and labeled according to the CLP regulation.
Hazard pictograms

Skull and Crossbones - GHS06

Signal word: Danger
Hazard statements
H301 Toxic if swallowed.
H332 Harmful if inhaled.
Precautionary statements
P261 Avoid breathing dust/fume/gas/mist/vapours/spray.
P264 Wash thoroughly after handling.
P304+P340 IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing.
P321 Specific treatment (see on this label).
P405 Store locked up.
P501 Dispose of contents/container in accordance with local/regional/national/international regulations.
WHMIS classification
D1A - Very toxic material causing immediate and serious toxic effects
Classification system
HMIS ratings (scale 0-4)
(Hazardous Materials Identification System)

Health (acute effects) = 1
Flammability = 0
Physical Hazard = 0
Other hazards
Results of PBT and vPvB assessment
PBT: Not applicable.
vPvB: Not applicable.


Chemical characterization: Substances
CAS# Description:
13494-80-9 Tellurium
Identification number(s):
EC number:


Description of first aid measures
General information
Immediately remove any clothing soiled by the product.
In case of irregular breathing or respiratory arrest provide artificial respiration.
After inhalation
Supply fresh air. If required, provide artificial respiration. Keep patient warm.
Seek immediate medical advice.
After skin contact
Immediately wash with water and soap and rinse thoroughly.
Seek immediate medical advice.
After eye contact
Rinse opened eye for several minutes under running water. Then consult a doctor.
After swallowing
Do not induce vomiting; immediately call for medical help.
Information for doctor
Most important symptoms and effects, both acute and delayed
No further relevant information available.
Indication of any immediate medical attention and special treatment needed
No further relevant information available.


Extinguishing media
Suitable extinguishing agents
Special powder for metal fires. Do not use water.
For safety reasons unsuitable extinguishing agents
Special hazards arising from the substance or mixture
If this product is involved in a fire, the following can be released:
Metal oxide fume
Hydrogen telluride
Advice for firefighters
Protective equipment:
Wear self-contained respirator.
Wear fully protective impervious suit.


Personal precautions, protective equipment and emergency procedures
Wear protective equipment. Keep unprotected persons away.
Ensure adequate ventilation
Environmental precautions:
Do not allow material to be released to the environment without proper governmental permits.
Do not allow product to reach sewage system or any water course.
Do not allow to penetrate the ground/soil.
Methods and material for containment and cleaning up:
Dispose of contaminated material as waste according to section 13.
Prevention of secondary hazards:
No special measures required.
Reference to other sections
See Section 7 for information on safe handling
See Section 8 for information on personal protection equipment.
See Section 13 for disposal information.


Precautions for safe handling
Keep container tightly sealed.
Store in cool, dry place in tightly closed containers.
Ensure good ventilation at the workplace.
Information about protection against explosions and fires:
No information known.
Conditions for safe storage, including any incompatibilities
Requirements to be met by storerooms and receptacles:
No special requirements.
Information about storage in one common storage facility:
Do not store together with acids.
Store away from strong bases.
Reacts with certain metals.
Store away from halogens.
Do not store with interhalogens.
Store away from oxidizing agents.
Further information about storage conditions:
Keep container tightly sealed.
Store in cool, dry conditions in well sealed containers.
Specific end use(s)
No further relevant information available.


Additional information about design of technical systems:
Properly operating chemical fume hood designed for hazardous chemicals and
having an average face velocity of at least 100 feet per minute.
Control parameters
Components with limit values that require monitoring at the workplace:
13494-80-9 Tellurium (100.0%)
PEL (USA) Long-term value: 0.1 mg/m³
as Te
REL (USA) Long-term value: 0.1 mg/m³
as Te
TLV (USA) Long-term value: 0.1 mg/m³
as Te
EL (Canada) Long-term value: 0.1 mg/m³
EV (Canada) Long-term value: 0.1 mg/m³
as tellurium
Additional information:
No data
Exposure controls
Personal protective equipment
General protective and hygienic measures
The usual precautionary measures for handling chemicals should be followed.
Keep away from foodstuffs, beverages and feed.
Remove all soiled and contaminated clothing immediately.
Wash hands before breaks and at the end of work.
Maintain an ergonomically appropriate working environment.
Breathing equipment:
Use suitable respirator when high concentrations are present.
Protection of hands:
Impervious gloves
Check protective gloves prior to each use for their proper condition.
The selection of suitable gloves not only depends on the material, but also on quality. Quality will vary from manufacturer to manufacturer.
Penetration time of glove material (in minutes)
Not determined
Eye protection:
Safety glasses
Body protection:
Protective work clothing.


Information on basic physical and chemical properties
General Information
Form: Solid in various forms
Color: Silvery-white
Odor: Odorless
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 449.5 °C (841 °F)
Boiling point/Boiling range: 989.8 °C (1814 °F)
Sublimation temperature / start: Not determined
Flammability (solid, gaseous)
Not determined.
Ignition temperature: Not determined
Decomposition temperature: Not determined
Auto igniting: Not determined.
Danger of explosion: Not determined.
Explosion limits:
Lower: Not determined
Upper: Not determined
Vapor pressure: Not applicable.
Density at 20 °C (68 °F): 6.24 g/cm³ (52.073 lbs/gal)
Relative density
Not determined.
Vapor density
Not applicable.
Evaporation rate
Not applicable.
Solubility in / Miscibility with Water: Insoluble
Partition coefficient (n-octanol/water): Not determined.
dynamic: Not applicable.
kinematic: Not applicable.
Other information
No further relevant information available.


No information known.
Chemical stability
Stable under recommended storage conditions.
Thermal decomposition / conditions to be avoided:
Decomposition will not occur if used and stored according to specifications.
Possibility of hazardous reactions
Reacts with certain metals.
Conditions to avoid
No further relevant information available.
Incompatible materials:
Oxidizing agents
Hazardous decomposition products:
Metal oxide fume
Hydrogen telluride


Information on toxicological effects
Acute toxicity:
Toxic if swallowed.
The Registry of Toxic Effects of Chemical Substances (RTECS) contains acute toxicity data for components in this product.
LD/LC50 values that are relevant for classification:
Oral LD50 83 mg/kg (rat)
Inhalative LC50/4H >2420 mg/m3/4H (rat)
Skin irritation or corrosion:
No irritant effect.
Eye irritation or corrosion:
May cause irritation
No sensitizing effects known.
Germ cell mutagenicity:
No effects known.
No classification data on carcinogenic properties of this material is available from the EPA, IARC, NTP, OSHA or ACGIH.
Reproductive toxicity:
No effects known.
Specific target organ system toxicity - repeated exposure:
No effects known.
Specific target organ system toxicity - single exposure:
No effects known.
Aspiration hazard:
No effects known.
Subacute to chronic toxicity:
The Registry of Toxic Effects of Chemical Substances (RTECS) contains multiple dose toxicity data for this substance.
Additional toxicological information:
To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.
The Registry of Toxic Effects of Chemical Substances (RTECS) contains reproductive and/or mutation data for components in this product.


Aquatic toxicity:
No further relevant information available.
Persistence and degradability
No further relevant information available.
Bioaccumulative potential
No further relevant information available.
Mobility in soil
No further relevant information available.
Additional ecological information:
General notes:
Do not allow material to be released to the environment without proper governmental permits.
Do not allow undiluted product or large quantities to reach ground water, water course or sewage system.
Avoid transfer into the environment.
Results of PBT and vPvB assessment
Not applicable.
Not applicable.
Other adverse effects
No further relevant information available.


Waste treatment methods
Consult state, local or national regulations to ensure proper disposal.
Uncleaned packagings:
Disposal must be made according to official regulations.


Not applicable
UN proper shipping name
Not applicable
Transport hazard class(es)
Not applicable
Packing group
Not applicable
Environmental hazards:
Not applicable.
Special precautions for user
Not applicable.
Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code
Not applicable.
Transport/Additional information:
Marine Pollutant (DOT):


Safety, health and environmental regulations/legislation specific for the substance or mixture
National regulations
All components of this product are listed in the U.S. Environmental Protection Agency Toxic Substances Control Act Chemical substance Inventory.
All components of this product are listed on the Canadian Domestic Substances List (DSL).
SARA Section 313 (specific toxic chemical listings)
Substance is not listed.
California Proposition 65
Prop 65 - Chemicals known to cause cancer
Substance is not listed.
Prop 65 - Developmental toxicity
Substance is not listed.
Prop 65 - Developmental toxicity, female
Substance is not listed.
Prop 65 - Developmental toxicity, male
Substance is not listed.
Information about limitation of use:
For use only by technically qualified individuals.
Other regulations, limitations and prohibitive regulations
Substance of Very High Concern (SVHC) according to the REACH Regulations (EC) No. 1907/2006.
Substance is not listed.
The conditions of restrictions according to Article 67 and Annex XVII of the Regulation (EC) No 1907/2006 (REACH) for the manufacturing, placing on the market and use must be observed.
Substance is not listed.
Annex XIV of the REACH Regulations (requiring Authorisation for use)
Substance is not listed.
REACH - Pre-registered substances
Substance is listed.
Chemical safety assessment:
A Chemical Safety Assessment has not been carried out.


Safety Data Sheet according to Regulation (EC) No. 1907/2006 (REACH). The above information is believed to be correct but does not purport to be all inclusive and shall be used only as a guide. The information in this document is based on the present state of our knowledge and is applicable to the product with regard to appropriate safety precautions. It does not represent any guarantee of the properties of the product. American Elements shall not be held liable for any damage resulting from handling or from contact with the above product. See reverse side of invoice or packing slip for additional terms and conditions of sale. COPYRIGHT 1997-2016 AMERICAN ELEMENTS. LICENSED GRANTED TO MAKE UNLIMITED PAPER COPIES FOR INTERNAL USE ONLY.

Tellurium Isotopes

Tellurium has six stable isotopes: 120Te, 122Te, 123Te, 124Te, 125Te and 126Te.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
105Te 104.94364(54)# 1# µs Unknown 5/2+# N/A 845.82 -
106Te 105.93750(14) 70(20) µs [70(+20-10) µs] a to 102Sn 0+ N/A 863.21 -
107Te 106.93501(32)# 3.1(1) ms a to 103Sn; ß+ to 107Sb 5/2+# N/A 871.29 -
108Te 107.92944(11) 2.1(1) s ß+ to 108Sb; a to 104Sn; ß+ + p to 107Sb; ß+ + a to 104Ln 0+ N/A 888.68 -
109Te 108.92742(7) 4.6(3) s ß+ to 109Sb; ß+ + p to 108Sb; a to 105Sn ; ß+ + a to 105Ln (5/2+) N/A 896.76 -
110Te 109.92241(6) 18.6(8) s ß+ to 110Sb; ß+ + p to 110Sb 0+ N/A 904.84 -
111Te 110.92111(8) 19.3(4) s ß+ to 111Sb (5/2)+# N/A 912.92 -
112Te 111.91701(18) 2.0(2) min ß+ to 112Sb 0+ N/A 930.31 -
113Te 112.91589(3) 1.7(2) min ß+ to 113Sb (7/2+) N/A 938.39 -
114Te 113.91209(3) 15.2(7) min ß+ to 114Sb 0+ N/A 946.47 -
115Te 114.91190(3) 5.8(2) min ß+ to 115Sb 7/2+ N/A 954.55 -
116Te 115.90846(3) 2.49(4) h EC to 116Sb 0+ N/A 971.95 -
117Te 116.908645(14) 62(2) min EC to 117Sb 1/2+ N/A 980.02 -
118Te 117.905828(16) 6.00(2) d EC to 118Sb 0+ N/A 988.1 -
119Te 118.906404(9) 16.05(5) h EC to 119Sb 1/2+ 0.25 996.18 -
120Te 119.90402(1) Observationally Stable - 0+ N/A 1004.26 0.09
121Te 120.904936(28) 19.16(5) d EC to 121Sb 1/2+ N/A 1012.34 -
122Te 121.9030439(16) STABLE - 0+ N/A 1020.42 2.55
123Te 122.9042700(16) >600E+12 y - 1/2+ -0.73679 1028.5 0.89
124Te 123.9028179(16) STABLE - 0+ N/A 1036.58 4.74
125Te 124.9044307(16) Observationally Stable - 1/2+ -0.88828 1044.65 7.07
126Te 125.9033117(16) STABLE - 0+ N/A 1052.73 18.84
127Te 126.9052263(16) 9.35(7) h ß- to 127I 3/2+ 0.64 1060.81 -
128Te 127.9044631(19) 2.2(3)E+24 y - to 128Xe 0+ N/A 1068.89 31.74
129Te 128.9065982(19) 69.6(3) min ß- to 129I 3/2+ 0.7 1076.97 -
130Te 129.9062244(21) 790(100)E+18 y - to 130Xe 0+ N/A 1085.05 -
131Te 130.9085239(21) 25.0(1) min ß- to 131I 3/2+ N/A 1093.13 -
132Te 131.908553(7) 3.204(13) d ß- to 132I 0+ N/A 1101.21 -
133Te 132.910955(26) 12.5(3) min ß- to 133I (3/2+) N/A 1099.97 -
134Te 133.911369(11) 41.8(8) min ß- to 134I 0+ N/A 1108.05 -
135Te 134.91645(10) 19.0(2) s ß- to 135I (7/2-) N/A 1116.12 -
136Te 135.92010(5) 17.63(8) s ß- to 136I; ß- + n to 135I 0+ N/A 1114.89 -
137Te 136.92532(13) 2.49(5) s ß- to 137I; ß- + n to 136I 3/2-# N/A 1122.97 -
138Te 137.92922(22)# 1.4(4) s ß- to 138I; ß- + n to 137I 0+ N/A 1131.04 -
139Te 138.93473(43)# 500# ms [>300 ns] ß- to 139I; ß- + n to 138I 5/2-# N/A 1129.81 -
140Te 139.93885(32)# 300# ms [>300 ns] ß- to 140I; ß- + n to 139I 0+ N/A 1137.89 -
141Te 140.94465(43)# 100# ms [>300 ns] ß- to 141I; ß- + n to 140I 5/2-# N/A 1136.65 -
142Te 141.94908(64)# 50# ms [>300 ns] ß- to 142I 0+ N/A 1144.73 -