A cross-linkable silicone composition comprising at least the following components: an organopolysiloxane represented by the following average unit formula: (R 1 3 SiO 1/2) a (R 1 2 SiO 2/2) b (R 1 SiO 3/2) c (SiO 4/2) d (R 2 O 1/2) e (where R 1 are phenyl groups, alkyl or cycloalkyl groups having 1 to 6 carbon atoms, or alkenyl groups having 2 to 6 carbon atoms and where 60 to 80 mole % of R 1 are phenyl groups and 10 to 20 mole % of R 1 are alkenyl groups; R 2 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and "a", "b", "c", "d", and "e" are numbers that satisfy the following conditions: 0 ≤ a ≤ 0.2; 0.2 ≤ b ≤ 0.7; 0.2 ≤ c ≤ 0.6; 0 ≤ d ≤ 0.2; 0 ≤ e ≤ 0.1; and a + b + c + d =1); an organopolysiloxane represented by the following general formula: R 3 3 SiO (R 3 2 SiO) m SiR 3 3 (where R 3 are phenyl groups, alkyl or cycloalkyl groups having 1 to 6 carbon atoms, or alkenyl groups having 2 to 6 carbon atoms and where 40 to 70 mole % of R 3 are phenyl groups and at least one R 3 is an alkenyl group; and "m" is an integer in the range of 5 to 100) {this composition is used in an amount of 0 to 20 parts by weight per 100 parts by weight of component}; an organopolysiloxane having in one molecule two silicon-bonded hydrogen atoms and where phenyl groups constitute 30 to 70 mole % of silicon-bonded organic groups {the mole ratio of silicon-bonded hydrogen atoms contained in this component to the total sum of alkenyl groups contained in components and is in the range of 0.5 to 2}; and a hydrosilylation catalyst in an amount sufficient to promote a hydrosilylation reaction between the alkenyl groups contained in components and and silicon-bonded hydrogen atoms contained in component. an organopolysiloxane represented by the following average unit formula: (R 1 3 SiO 1/2) a (R 1 2 SiO 2/2) b (R 1 SiO 3/2) c (SiO 4/2) d (R 2 O 1/2) e (where R 1 are phenyl groups, alkyl or cycloalkyl groups having 1 to 6 carbon atoms, or alkenyl groups having 2 to 6 carbon atoms and where 60 to 80 mole % of R 1 are phenyl groups and 10 to 20 mole % of R 1 are alkenyl groups; R 2 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and "a", "b", "c", "d", and "e" are numbers that satisfy the following conditions: 0 ≤ a ≤ 0.2; 0.2 ≤ b ≤ 0.7; 0.2 ≤ c ≤ 0.6; 0 ≤ d ≤ 0.2; 0 ≤ e ≤ 0.1; and a + b + c + d =1); an organopolysiloxane represented by the following general formula: R 3 3 SiO (R 3 2 SiO) m SiR 3 3 (where R 3 are phenyl groups, alkyl or cycloalkyl groups having 1 to 6 carbon atoms, or alkenyl groups having 2 to 6 carbon atoms and where 40 to 70 mole % of R 3 are phenyl groups and at least one R 3 is an alkenyl group; and "m" is an integer in the range of 5 to 100) {this composition is used in an amount of 0 to 20 parts by weight per 100 parts by weight of component}; an organopolysiloxane having in one molecule two silicon-bonded hydrogen atoms and where phenyl groups constitute 30 to 70 mole % of silicon-bonded organic groups {the mole ratio of silicon-bonded hydrogen atoms contained in this component to the total sum of alkenyl groups contained in components and is in the range of 0.5 to 2}; and a hydrosilylation catalyst in an amount sufficient to promote a hydrosilylation reaction between the alkenyl groups contained in components and and silicon-bonded hydrogen atoms contained in component.