A curable silicone composition characteristically comprises 100 mass parts of an alkenyl-containing organopolysiloxane comprising (A-1) a dialkylpolysiloxane that has an average of at least two alkenyl groups in each molecule and a viscosity at 25°C of at least 1,000 mPa · s to not more than 50,000 mPa · s, at from 50 mass% to not more than 80 mass% of component, and (A-2) an alkenyl-containing, resin-form organopolysiloxane that comprises the Si0 4/2 unit, R 1 2 R 2 SiO 1/2 unit, and R 1 3 SiO 1/2 unit wherein R 1 is C 1-10 alkyl and R 2 is alkenyl and that contains the alkenyl group in the range from at least 1.0 mass% to less than 3.5 mass%, at from 20 mass% to not more than 50 mass% of component; an organopolysiloxane that has an average of at least three silicon-bonded hydrogen atoms in each molecule wherein the silicon-bonded groups other than the silicon-bonded hydrogen are C 1-10 alkyl, in an amount that provides 0.8 to 2 moles silicon-bonded hydrogen in this component per 1 mole of the total alkenyl in component; and a hydrosilylation reaction catalyst in a catalytic quantity, and provides a cured silicone material that characteristically has a hardness measured using the type A durometer specified in JIS K 6253 is in the range from at least 30 to not more than 80, the elongation as specified in JIS K 6251 is at least 50%, the parallel light transmittance at 25°C measured in accordance with JIS K 7105 on a 6 mm optical path length is at least 90%, and the parallel light transmittance at 200°C is a value that is at least 99% of the parallel light transmittance at 25°C. 100 mass parts of an alkenyl-containing organopolysiloxane comprising (A-1) a dialkylpolysiloxane that has an average of at least two alkenyl groups in each molecule and a viscosity at 25°C of at least 1,000 mPa · s to not more than 50,000 mPa · s, at from 50 mass% to not more than 80 mass% of component, and (A-2) an alkenyl-containing, resin-form organopolysiloxane that comprises the Si0 4/2 unit, R 1 2 R 2 SiO 1/2 unit, and R 1 3 SiO 1/2 unit wherein R 1 is C 1-10 alkyl and R 2 is alkenyl and that contains the alkenyl group in the range from at least 1.0 mass% to less than 3.5 mass%, at from 20 mass% to not more than 50 mass% of component; (A-1) a dialkylpolysiloxane that has an average of at least two alkenyl groups in each molecule and a viscosity at 25°C of at least 1,000 mPa · s to not more than 50,000 mPa · s, at from 50 mass% to not more than 80 mass% of component, and (A-2) an alkenyl-containing, resin-form organopolysiloxane that comprises the Si0 4/2 unit, R 1 2 R 2 SiO 1/2 unit, and R 1 3 SiO 1/2 unit wherein R 1 is C 1-10 alkyl and R 2 is alkenyl and that contains the alkenyl group in the range from at least 1.0 mass% to less than 3.5 mass%, at from 20 mass% to not more than 50 mass% of component; an organopolysiloxane that has an average of at least three silicon-bonded hydrogen atoms in each molecule wherein the silicon-bonded groups other than the silicon-bonded hydrogen are C 1-10 alkyl, in an amount that provides 0.8 to 2 moles silicon-bonded hydrogen in this component per 1 mole of the total alkenyl in component; and a hydrosilylation reaction catalyst in a catalytic quantity,